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TOOL-STEEL. 



TOOL-STEEL: 

A CONCISE HANDBOOK 

ON 

TOOL-STEEL IN GENERAL, 



ITS TREATMENT IN THE OPERATIONS OF FORGING, ANNEALING, 
HARDENING, TEMPERING, ETC. 

AND THE APPLIANCES THEREFOR. 



BY 

OTTO THALLNER, 

IRON-MASTER AND MANAGER IN CHIEF OF THE TOOL-STEEL WORKS, 
BISMARCKHl'TTE ON THE SAALE, GERMANY. 



AUTHORIZED TRANSLATION FROM THE GERMAN, 

BY 

WILLIAM T, BRANNT. 



ILLUSTRATED BY SIXTY-NINE ENGRAVINGS. 



PHILADELPHIA : 

HENRY CAREY BAIRD & CO., 

INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 
810 Walnut Street. 

LONDON : 

SAMPSON LOW, MARSTON & CO., Limited, 

ST. dtjnstan's house, fetter lane, fleet street. 

1902. 



o, 






\; A'i^ 



THE LIBRARY OF 
CONGRES*. 

T^, CoHlte RtCSlvED 

NOV. •> 1902 

Pi /is-s^-XXo No. 

corv H 



COPYRIGHT, BY 

HENRY CAREY BAIRD & CO. 

1902. 



Printed at the 

WICKERSHAM PRINTING HOUSE, 

63 and 55 North Queen Street, 

Lancaster, Pa., U. S. A. 



^ 



^^^C^ 



PREFACE. 

The changes which tool-steel undergoes by the various 
operations of forging, annealing, hardening, tempering, etc., 
have theoretically been established by Ledebur, Wedding, 
Reiser, Osmond, and others. 

The rules, which have been deduced from theory, of what 
has to be observed in the above-mentioned operations are in 
themselves of a simple nature and readily comprehended, 
and a more universal knowledge of them has been diffused 
by the scientific publications of the above-mentioned writers, 
as well as by the so-called " directions for the treatment " of 
the steel, which nearly every manufacturer of tool-steel 
furnishes to his customers. 

The almost sole object of these directions is to promote a 
more intimate knowledge of steel and its treatment in the 
manufacture of tools among those who are especially 
entrusted with it, but, as a rule, an explanation of " how 
and by what means " their observance is to be effected is 
wanting. 

The steel recommended by them is not seldom invested 
with mysterious properties, and encouragement is frequently 
given to the continuance of primitive appliances, but little 
suitable for the purpose and difficult to attend. 

In these directions the pith of the matter is very seldom 
treated of, or only in a very brief way, so that the changes 
which the steel undergoes in the various operations of the 
manufacture of tools remain, as a rule, not understood, and 
there is no probability of the mind being directed towards 
the necessity of suitable working appliances. 

Publications on this subject derived from practice are also 
scarce, because experiences gathered in this line are prefer- 
ably kept secret. 

(V) 



VI PREFACE. 

• 

These conditions apparently explain the limited general 
diffusion of a knowledge of practically approved appliances 
and working processes, in consequence of which master- 
workman and manufacturer are frequently placed in the 
disagreeable j)Osition of having to desist from making the 
most of the highest efficiencies attainable in tools, or are 
forced to work with a greater expense of time, money and 
material than would otherwise be necessary. 

The master-workman and the workmen entrusted with 
the manufacture of tools are under the necessity of gather- 
ing experience from their own practice, and it is largely left 
to themselves to devise appliances required for successful 
working without having at their disposal anything that will 
give them a clue to liow it is to be done. 

It was especially the latter condition that induced me to 
write this small work. 

It is chiefly intended as a guide to the master-workman 
and the intelligent tool-maker, and, in accordance with this 
object, is exclusively adapted to practical needs. 

As sources of the explanations derived from theory, 
which have been incorporated into the book, the scientific 
works and separate publications of the previously men- 
tioned authors have served. 

The general arrangement of the material has been 
modeled after the excellent work by F. Reiser : " Das 
Harten des Stables in Theorie und Praxis " (" Hardening 
of Steel in Theory and Practice"). 

The directions and working appliances collected in the 
book have throughout been taken from practice, and are 
intended to assist master-workmen and workmen employed 
in the practical execution of the various operations in the 
manufacture of tools, in their occupation, which demands 
varied knowledge and experience. 

The Author. 

BiSMARCKHUETTE ON SaALE. 



CONTENTS. 



INTRODUCTION. 

PAGE 

Products of iron -works used in the manufacture of tools; Tool-steel and 
various designations of it 1 

Crucible steel the most noble product of the manufacture of tool-steel; 
Weld steel and the product brought into commerce under this name ... 2 

I. 

Composition of Tool-Steel and its Classification According to It. 

Definition of steel; Various forms in which carbon occurs in iron; 
Hardening carbon 3 

Carbide; Graphitic carbon; Accidental admixtures in steel; On what the 
quality of steel depends , 4 

Quantity of injurious admixtures in steel; Silicon in crucible steel; In- 
tentionally added admixtures 5 

Manganese : Manganese steel ; Properties of actual manganese steel ; 
Tungsten 6 

Properties of steel to which tungsten has been added; Chromium 7 

Nickel; Molybdenum, titanium and vanadium 8 

II. 

Classification of Tool-Steel According to the Degree of Hardness 
AND the Purpose for which It is to be Used. 

Groups of commercial tool-steel; Tool-steel which acquires its hardness 
exclusively from a content of carbon; Tool-steel which in addition to 
carbon contains admixtures increasing the hardness, also called special 
steel 9 

Modes of labeling tool-steel; Designations for the degree of hardness 10 

Selection of tool-steel for a determined purpose; Standard in practice for 
the useful effect of the finished tool; Less attention required in working 

soft steel 11 

(Vii) 



Vni CONTENTS. 

FAOB 

Classification of steel according to the degree of hardness and the pur- 
poses for which it is to be employed as in use in Bismarck huette; Special 
steels 12 

Natural hard steel; Special turning steel; Magnet steel; Composition of 
self-hardened steel and of very hard special turning steel 13 

Composition of magnet steel; Tool steel for definite purposes 14 

Soft-centred or mild-centred steel, and mode of producing it 15 

III. 

Observations on the Exteknai, Appearance of Commercial 
Tool,-Steel. 
Defects which the surface of the steel may show, Scales; Cracks; Seams. 16 
Edge cracks; Appearance of the fracture; Structure of soft and of hard 

steel 17 

Defects which may be observed on the surfaces of the fractures of tool- 
steel; Flaws or blisters; Spots due to liquation; Flaws in the centre of 
the steel and their cause 18 

IV. 

Observations on the Fracture of Steel, with Regard to the Struc- 
ture IN THE Hardened and Non-Hardened States. 

Difference in the appearance of the structure of steel according to how it 
has been worked 19 

Conditions on which the appearance of the fracture of unhardened steel 
may depend 20 

Conditions on which the appearance of the fracture of hardened steel is 
dependent; Tables showing the influence of the various degrees of 
temperature upon hardened and unhardened steel, and their general 
application in practice 21 

V. 

Practice of the Fire-Treatment of Steel. 

Purpose of the repeated heating of steel in the manufacture of tools 22 

Proper adaptation of the appliances for heating; Choice of fuel; Disad- 
vantages which may result from the use of certain fuels 23 

Hard coke and furnace for heating the steel 24 

Smith-coal or forge coal 26 

Effect produced by a content of sulphur in the coal; Coke dust 26 



CONTENTS. IX 

PAGE 

Location of the highest degree of heat developed in an open fire; Diffi- 
culties encountered in heating in an open fire 27 

Conversion of an open fire into a provisional furnace 28 

Disagreeable feature in heating cutters; Construction of a unifHe in the 
open fire 29 

Unsuitableness of mild soft coke for forging and hardening from open 
fires; Advantages of charcoal for open fires 30 

Disadvantages resulting from the action of the blast upon tool-steel or the 
finished tool 31 

Mode of protecting the steel from the action of the blast; Weakening the 
effect of the blast; Eemedy for the attacks of the air upon the surface 
of the steel 32 

Disadvantages of open fires in making or repairing a large number of 
tools; Importance of the influence of light in judging the degree of 
temperature of the steel 33 

Location in the works of the devices for forging and hardening tools; 
Avoidance of drawbacks due to heating the steel in an open fire 34 

Most simple type of furnace; Construction of a furnace to be operated 
with coke 35 

Construction of a furnace to be operated with charcoal 38 

Furnace for heating long articles 39 

Construction of furnaces to be fitted for coal 40 

Conversion of a furnace into a regular niufHe furnace 41 

Construction of a muffle furnace to be worked with charcoal 42 

Muffle furnaces, the muffles of which are heated by gas; Heating muffles 

of refractory clay 43 

Ordinary forging reverberatory furnace 44 

Small reverberatory furnace for forging and hardening operations on a 

small scale; Reverberatory furnace with two hearths 45 

Small reverberatory furnace with step-grate and two hearths; Reverbera- 
tory furnace with a fire-place patented by Gasteiger, of Vienna 47 

Reverberatory furnace with muffle 48 

VL 

Appliances for Annealing Steel. 
Changes in the properties of strength of steel; Forging strains and their 
removal by annealing; General rule applying to annealing; Protection 
of tool-steel from the air by annealing it in vessels 49 



X CONTENTS. 

PAGE 

Hints for tlie jiraotical execution of annealing; Annealing in boxes; Con- 
struction of an annealing furnace for forged pieces 50 

Furnace for annealing steel in an annealing pot or in annealing boxes 52 

Control of the result of the annealing operation 54 

Annealing furnace for annealing long articles 55 

VII. 
Appliances por Hardening Steel. 

Importance of thoroughly uniform heating; Disadvantages of imperfect 
heating appliances 55 

Hints for liie choice of suitable appliances; Furnaces suitable for hard- 
ening 56 

Methods for hardening tools in a bath of molten metal or in a bath of 
fused salts; Possibility of overheating of the melted mass 57 

Furnace and crucible for melting the metals or salts; Advantages of the 
use of a pyrometer; Disadvantages which may arise from heating steel 
in melted lead 58 

Mode of preventing melted lead from adhering to some portions of the 
tool; Heating steel in fused salts; Mixture of salts 59 

Fusion of the salts; Addition of yellow prussiate of potash; Preparation 
of the articles to be heated; Suspension of the articles in the melt 60 

Unequal heating of the melt and its detection; Advantages of heating 
tools in melted salt 61 

VIII. 
Hardening of Tool-Steel in General. 

What is understood by hardening; Hardening temperature; Definition of 
temper color; Appearance of the temper colors 62 

General custom of tempering finished tools; Requirements for the appear- 
ance of the temper colors; Conditions to which the changes steel under- 
goes in hardening are chiefly due 63 

Changes in the dimensions of the steel, illustrated 64 

Strains in the steel before it is hardened not removed by simply heating 
in hardening; Practical utilization of the property of steel of assuming 
fixed dimensions in hardening operations succeeding one another 65 

Observations on the fractures of tool-steel of the same degree of hardness 
notched at various distances from each other, and then hardened and 
broken on the notched places 66 



CONTENTS. XI 

PAGE 

Illustration of the cross-section of steel not hardened and of the cross- 
section of the same steel hardened 67 

Cause of cracking; Cracking from the interior 68 

Observations on the fracture of hardened steel of a larger cross-section; 

Severance of the corners of a cube, illustrated 69 

Examples of the force of the strain in forming cracks, illustrated 70 

Distortions of the steel caused by strains, illustrated 71 

■Change in the cross-section of tools by hardening; Prevention of cracking; 
Influence of manganese upon the change in volume of the steel in 
hardening 72 

IX. 
Hardening of Tools Which Are to be Hardened in Their Entirety. 

Cause of cracking and means of avoiding it; Prevention of cracking by 

letting-down ; Portions of tools especially subject to snapping oflT; 

Cracking from the interior 73 

Effect of letting-down; Cause of the snapping off of the teeth of a cutter... 74 
Avoidance of superficial scale-like separations on tools; Prevention against 

a tool completely losing its hardness 75 

Reheating in hot sand or in hot water 76 

Process of allowing the hardened tool to remain in the hardening bath 

until it is entirely cold; Practical application of this process 77 

Division of tools into several sections 78 

Diminution of strains by boring out a tool; Main points to be considered 

in the construction of a tool 79 

X. 

Hardening of Tools which are only to be Partially Hardened. 

Division of partial hardening into three groups 80 

Mode of heating; Overheating of broad cutters; Powder for cooling off... 81 
Heating tools all over which are to be partially hardened; Experiment 

with a bar of steel 82 

Hardening tools so that there is a gradual transition of the hardened into 

the luihardened portions 83 



Xll CONTENTS. 

PAGE 

XI. 

Cooling of Tooi^ in Hardening and Dkvicek for this Purpose. 

General rule for heating tools for hardening; Formation of steam in the 
hardening bath, and its effect 83 

Hardening of especially large and heavy tools; Uneven cooling before 
hardening, and its effect 84 

Formation of cracks by catching the red-hot tool with cold tongs, illus- 
trated by an example 85 

Correct and incorrect forms of tongs; Covering portions not to be hard- 
ened 86 

Intentional uneven cooling by covering portions of the tool, illustrated by 
examples 87 

Cooling of tools which have to be heated in their entirety; Mode of using 
running water for hardening 89 

Use of falling water for hardening and device for this purpose 90 

Equalization of strains formed by hardening, and device for this purpose. 91 

Device for hardening if a water conduit or running water is not available. 92 

Object of hardening in an ascending water jet; Simultaneous use of a 
falling and ascending water jet; Device for hardening in an ascending 
water jet 93 

Method of hardening by means of a jet if the operation of hardening is to 
be effected in a large reservoir; Hardening of hollow bodies, and 
devices for that purpose 95 

XII. 

Liquids Used in Quenching Steel. 

Pure water; Most suitable temperature of the hardening water; Com- 
position of water; Increase in the heat-conducting power of water by 
salts and acids 97 

Means for les.sening the too intense hardening effect of well or spring 
water; Favorable effiect of hardening water which has been used for 
sometime; Hardening water mixed with soluble constituents 98 

Common salt; Soda (carbonate of soda); Acids; Use of acidulated water. 99 

Alcohol; Soap; Effects of soluble admixtures of organic nature; Harden- 
ing water mixed with insoluble constituents 100 

Hardening water mixed with oils or fats 101 



CONTENTS. Xlll 

PAGE 

Oils and fats; Precaution in using fat or oil for hardening; Metals; Mer- 
cury 102 

Tin, zinc and lead; Change in the properties of steel cooled in melted 
metals 103 

Gaseous cooling agents; Solid bodies as cooling agents 104 

Results obtained in Bismarckhuette by experiments regarding the cutting 
power of medium hard tool-steel hardened in various cooling agents... 105 

XIII. 

Tempering of Hardened Steel, and Devices for this Purpose. 

Various ways in which tempering may be effected; Tempering from the 

interior 105 

Recognition of the advance of the heat by the progression of the temper 
colors; To impart special toughness to a tool which in use is exposed 

to shock and blow 106 

Progression of cracks, illustrated by an example; Tempering from the 

interior 107 

Tempering from the interior assisted by simultaneous heating from the 

outside; An error frequently committed in cooling 108 

Precaution in tempering from the outside; Requisite for tempering tools. 109 
Effect of the duration of time in tempering, and its practical utilization; 

Blazing off with oil 110 

Tempering small tools in oil, and device for that purpose Ill 

Tempering in an open fire, upon red-hot iron and by means of a gas flame. 112 

Tempering by means of hot sand, and devices for that purpose 113 

Tempering of long knives and furnace for that purpose 114 

Ck)oling tempered tools 115 

Error frequently committed in tempering partially hardened tools 116 

XIV. 

Straightening Tools. 

Methods by means of which straightening may be effected; Cause of dis- 
tortion of tools during hardening; Straightening claws and their use . . 117 

Tools required for straightening; Straightening of tools by uneven heat- 
ing and cooling in tempering 118 



XIV CONTENTS. 

PAGE 

XV. 

Case-Hardening and Preventatives a<;ainst Superficial Decabboni- 
zation and overheating. 

Object of case-hardening; Effect on the structure of iron or steel when 

heating with carbon is effected at a high temperature 119 

Method pursued in the operation of case-hardening; Application of case- 
hardening in practice 120 

Manner of packing a spindle which is to be iiard in two places, illustrated. 121 

Burning in, and mode of effecting this operation 122 

Hardening paste and its preparation 123 

Dry hardening powder and its composition; Agents for cooling tools 124 

Cooling of unevenly heated tools; Compositions of suitable powders; 

Mode of applying the powder 125 

Mixtures which are to be applied in a pasty condition 126 

Carbon compounds in a gaseous form for case-hardening; Use of pig-iron 
for case-hardening 127 

XVI. 

Welding of Steel. 

Heating steel for welding 127 

Agents which assist in the formation of a soft layer on the surface of the 
steel; Operation of welding 128 

XVII. 

Regeneration of Steel which has been Spoiled in the Fire. 

Steel burnt and overheated 129 

Mode of restoring the fine structure of the steel when tools have been 
overheated; Definitions of roasted or baked steel, and of dead steel 130 

XVIII. 

Investigations of Defects of Hardened Tools. 
What experience in hardening includes; Test operation with one piece... 131 
Overheating; Severance of corners and edges of larger tools; Uncertainty 

and timidity in hardening; Hints for the inspection of tools 132 

Observations on the fracture of the tool; What curved cracks on flat tools 
indicate 133 



CONTENTS. XV 

PAGE 

Failure due to incorrect cooling; Tools cracked from the interior; Cracks 
or separation of corners; Edge cracks; Uneven degree of hardness 134 

Cause of uniform degree of insuflBcient hardness; Soft spots; Soft skin on 
the surface of a hardened tool; Tools roasted or baked 135 

Defects noticed in using tools; Experiments at Bismarckhuette as to the 
efficiency of tools 136 

Increase in efficiency by a suitable process of cooling; Defect very fre- 
quently observed on very hard cutting tools caused by grinding upon 
hard, rapidly-revolving emery wheels 137 

Defects of tools with engraved surfaces; Notching of tools and prevention. 138 

Examination of tools which prove defective in use 139 

XIX. 

Improving the Pbopkkties of Strength of Steel. 

Object of improving the properties of strength of steel; Properties of steel 
rolled or forged at a high temperature; Efl'ects of the operations of hard- 
ening and tempering 140 

Most useful methods for improving and regulating the properties of 
strength of steel 141 

APPENDIX. 

(Jonditions which confront the toolsmith or locksmith; Demands made on 

foremen and workmen 142 

Primitive character of appliances which are frequently required; Mode of 
working to be observed in forging, annealing, hardening and tempering 

tools frequently called for; Hand chisels 143 

Hot and cold chisels; Rivet chisels (for cutting off rivet heads); Center 

bits 144 

Turning knives and planing knives; EoU-turning knives 145 

Screw-taps 146 

Screw-dies 147 

Broaches; Spiral drills for metal 148 

Common drills; Cutters 149 

Method of cooling wood-cutters of harder steel in molten metal ; Pipe 

cutters 152 

Milling tools; Hammers (hand hammers, riveting hammers, sledge ham- 
mers, etc.) 153 



XVI CONTENTS. 

■ PAGE 

Hammer swages 154 

Cause of defects in swages 155 

Round and circular shear knives (roll shear knives); Shear knives 156 

Device for letting down shear knives 158 

Machine knives for cutting paper, knives for splitting leather, planing 

and cutting knives for wood; Stamping knives for stamping out leather 

(soles and heels), paper, pasteboard, bristolboard, etc 159 

Circular knives (simple, straight and plate knives); Punches and dies.... 160 

Stamps and dies; Punches and dies for perforating holes in metals 162 

Mandrils for drawing metal cases and tubes; Draw plates 164 

Pillow blocks and pivots; Stone-working tools; Tools for the manufacture 

of nails 165 

Balls; Hardening small balls used for bearings; Difficulty in hardening 

large balls 166 

Tongs for handling balls; Device for hardening large balls 167 

Rolls; Process of hardening a large roll, illustrated by an example 168 

Appliance for hardening the roll 171 

Table for the conversion of centimeters to inches 172 

Index 173 



TOOL-STEEL. 



INTRODUCTION. 

In a wider sense, nearly all the products of iron-works, 
commencing with pig iron up to weld-iron and ingot-iron, 
which are not capable of being hardened, are employed in 
the manufacture of tools. However, in a narrower sense, 
iron which is capable of being hardened, i. e., steel, has, 
under the general designation of tool-steel, to be chiefly 
taken into consideration for the manufacture of tools. 

In many cases tool-steel is still more closely designated 
according to the smelting processes from which it has 
resulted, such as ingot-steel, weld-steel ; or according to the 
method of production, such as Bessemer steel, Martin steel, 
crucible steel, puddled steel, shear steel, etc.; further accord- 
ing to certain peculiarities, such as natural or self-hardened 
steel, hard-centred steel, soft-centred or mild-centred steel, 
tungsten-steel, chrome-steel, nickel-steel, etc.; and finally, 
according to the purposes to which it is to be applied, such 
as knife-steel, scythe-steel, magnet-steel, punch-steel, chisel- 
steel, etc. 

Beside the above-mentioned designations, there are also 
in use several of an allegorical nature, such as diamond- 
steel, self-hardener, boreas, atlas-steel, universal steel, etc., 
and others which intimate an alloy — which, however, as a 
rule, cannot be authenticated — to improve the quality of 

(1) 



TOOL-STEEL. 



the steel, such as titanium-steel, aluminium-steel, vanadium- 
steel, etc. 

The most noble product of the manufacture of tool-steel 
is crucible-steel, i. e., steel made by remelting in a crucible 
basis-materials in themselves very pure and of excellent 
quality. The object of this process is to obtain a thoroughly 
uniform product as free as possible from injurious admix- 
tures, and in the preparation of it every precaution is taken 
to avoid mistakes which might impair the quality of the 
finished tool-steel. Hence crucible-steel is rather expensive 
and for this reason ingot-steel produced by the Bessemer 
and Martin processes is largely used for inferior purposes. 

This steel is generally brought into commerce under the 
simple designation of " cast steel," and by many consumers 
is worked in good faith as crucible steel. 

The steel for the manufacture of tools brought into com- 
merce under the name of " weld-steel " is practically, as a 
rule, steel capable of being welded or hardened without 
regard as to whether or not it is weld-steel according to the 
smelting processes by means of which it has been produced. 
In most cases the product brought into commerce under 
the name of weld-steel is " weldable ingot steel." 



I. 

COMPOSITION OF TOOL-STEEL AND ITS CLASSI- 
FICATION ACCORDING TO IT. 

"^ Iron, which by being heated to a red heat and suddenly 
cooled, has acquired such hardness that it is not attacked 
by a file is, generally speaking, called steel. This property 
of iron results from a content of carbon which may amount 
to between 0.5 and 2 per cent. 

Iron with less than 0.5 per cent, carbon * does not 
acquire such a high degree of hardness, and with more 
than 2 per cent, carbon, it becomes pig-iron, and beside 
losing the capacity of being hardened, also loses the prop- 
erty of malleability. 

It has been shown by scientific researches that in iron, 
carbon occurs in various forms, the most important of which 
are as follows : 

a. Carbon fixed to the iron forming a chemical combina- 
tion with it (hardening carbon). 

This form of carbon appears to be the carrier of the hard- 
ening capacity in steel, and the process which takes place 
thereby has scientifically been determined as follows : 

When iron containing carbon is allowed slowly to cool 

* The transition from iron incapable of being hardened to steel which can be 
hardened is a gradual one, and the limit between them cannot be expressed by 
the content of carbon alone. The limit mentioned above refers to crucible- 
steel of the lowest degree of hardness used for hardened tools. 

(3) 



4 TOOL-STEEL. 

from the melting temperature, the carbon present forms 
with a portion of the iron a combination which is net-like 
diffused throughout the iron. (Carbide.) 

When such iron is heated to a cherry-red heat, the carbon 
present is uniformly absorbed (dissolved) by the iron and 
becomes hardening carbon. By quickly cooling the heated 
steel the carbon becomes fixed in this state, and the steel is 
hardened. If, however, the steel is allowed to cool slowly, 
the carbon is separated from its uniform combination with 
the iron and again forms with a portion of the latter the 
net-like diffused carbide. 

The larger the quantity of carljon (carbide) present, the 
more of it can during the process of hardening be converted 
into hardening carbon, and the greater will be the degree 
of hardness which the steel acquires. 

b. The carbon may occur in a free form visibly imbedded 
between the particles of iron (graphite). 

Graphitic carbon cannot be converted by the operation 
of hardening into hardening carbon, and hence does not in- 
duce hardening. It is a chief constituent of gray pig iron. 
It occurs very seldom in tool-steel and, when present, exerts 
an injurious influence upon its quality. 
■^ Besides iron and carbon, steel contains other substances 
which are either accidental admixtures, or are added for a 
special purpose. Phosphorus, sulphur, copper and arsenic 
are the principal accidental admixtures, and they exert 
always an injurious effect. A few hundredths of one per 
cent, of either of these substances suffice to render steel 
partially or entirely unfit for the manufacture of tools. 
The quality of steel is dependent on the quantity of injur- 
ious constituents it contains, and the total sum of them 
may serve as an expression in figures of its value. 



COMPOSITION OF TOOL-STEEL. O 

In tool-steel it is sought to avoid, as much as possible, 
the occurrence of injurious impurities, and in its production 
materials free from them are, as a rule, only used. Hence, 
the quantity of injurious admixtures in tool-steel is never 
so large that their presence could at once be inferred from 
its physical behavior in working. 

No matter what the nature of the injurious admixtures 
may be, it shows itself chiefly by brittleness in tool-steel 
when in the hardened state, and with an abundance of im- 
purities, also in the unhardened state.* 

Crucible cast-steel generally contains silicon as a fortu- 
itous admixture which has been absorbed b}' melting in 
the crucible. This content of silicon is, however, seldom 
so great as to exert an essential influence upon the qualit}'^ 
of the steel. A higher content of silicon promotes the 
edge-holding capacity, but also increases the brittleness 
of the steel, and is injurious when it causes a partial 
separation of the carbon in graphitic form. The fracture 
of such steel shows a dark grain. 

^ Intentionally are added to tool-steel the following metals, 
with the expectation of improving thereby the quality : 

* Numerous chemical and practical investigations in Bismarckliiitte regard- 
ing the qualitative value of tool-steel dependent on the degree of impurities 
have shown that the total amount of phosphorus, sulphur and copper should 
not exceed 0.06 per cent., if the material is, according to practical conditions, 
to be classed as "very good" tool-steel. Steel which contains a total of 0.10 
per cent, of phosphorus, sulphur and copper may be designated as "good" 
tool-steel, and when it contains more than this amount, as "medium" to 
"bad" tool-steel. 

Since the tenacity of steel decreases with an increase in the content of car- 
bon, the effect of injurious admixtures is essentially greater in harder than iu 
softer steel, so that the figures given above may be somewhat raised with soft 
steel and somewhat lowered with hard steel. 



6 TOOL-STKKL. 

Manganese, tungsten, chromium, nictel, and more seldom 
molybdenum and other metals. 

MANGANESE, 

Every kind of tool-steel contains manganese, the quan- 
tity in the ordinary product being from 0.2 to 0.5 per cent. 
Within these narrow limits manganese does not exert any 
considerable influence upon the properties of the steel, the 
strength, hardness and cutting power being slightly in- 
creased. On the other hand, it is th^e task of manganese to 
remove or fix during the fusing processes the gases and the 
oxides which are present in great abundance in liquid 
steel, and thus cause the production of dense castings free 
from blisters. 

Under the name " manganese steel," a tool-steel witli the 
normal content of manganese is brought into commerce. 
Very likely it bears this name only for the purpose of 
indicating that the steel has been malted with a content 
of manganese, and hence is freer from pores and cracks 
than other steel. Actual manganese steel which contains a 
considerable quantity of manganese (8 to 20 per cent.) is 
particularly strong, tough, and of such great natural hard- 
ness that it can scarcely be worked. 

Such manganese steel is brought into commerce in the 
form of finished tools, such as hatchets, axes, etc., or as 
material for machine-parts which are to possess special 
hardness and strength. 

TUNGSTEN. 

Tungsten is added to tool-steel if its hardness is to be 
essentially increased and its properties of strength arc to be 
improved. Up to 10 per cent, of tungsten is found in tool- 



COMPOSITION OF TOOL-STEEL. 7 

steel ; seldom more, but generally 2 to 4 per cent., and 
occasionally — especially in English steel — less than 1 per 
cent. 

A larger content of tungsten — over 2 per cent. — imparts 
to the steel, even while in an unhardened condition, a fine- 
grained structure of characteristic lustre. Hardened steel 
alloyed with tungsten shows even in the presence of very 
small quantities of it a ver}^ fine grain of dull lustre. With 
a higher content of tungsten the structure becomes so fine 
and velvety that the grain can scarcely be recognized with 
the naked eye. 

By a content of tungsten the hardness and edge-holding 
power of the steel are increased, but in a hardened state its 
tenacity is decreased. Hence, tool-steel with a content of 
tungsten is generally used only for tools which are to be 
gently engaged and are to possess great hardness and edge- 
holding power. By repeated treatment in the fire, steel 
which contains tungsten or chromium loses its good quali- 
ties much more rapidly than steel free from these constitu- 
ents, the edge-holding power decreasing very rapidly, while 
brittleness and tendency towards cracking in hardening 
increase. The sensitiveness of such steel towards over- 
heating is also much greater. 

CHROMIUM. 

Chromium is added to tool steel for the same purpose as 
tungsten, but not with the same result, since it does not 
possess the same efficiency and makes the steel much more 
brittle. 

Up to 3 per cent, of chromium is found in tool-steel ; 
generally 2.5 per cent, in very hard turning tools, and 



8 tool-step:l. 

more seldom less than 1 per cent, in softer steels (in some 
English varieties of steel). 

The property of chromium to make steel especially resist- 
ant to blow and shock has led to the special use of chrome- 
steel for shells, and in conjunction with nickel, for armor 
plates. 

The appearance of the fracture of steel is influenced by a 
content of chromium in a similar manner as by a content 
of tungsten. 

NICKEL. 

Nickel greatly improves the strength of steel, its hardness 
and tenacity in an unhardened state being essentially in- 
creased. In a hardened state nickel does not act in the 
same degree as tungsten or chromium, so that its use in 
tool-steel may be left out of consideration and nickel-steel 
to be emplo3'ed in an unhardened state need chiefly be 
mentioned. 

Machine-parts on which heavy demands are made, and 
which, either to save weight or space, are to have as small 
dimensions as possible, or the strength of which is to be 
especially increased, such as propeller-shafts, crank-i)ins, 
etc., are frequently constructed of nickel-steel, but its great- 
est application is for armor-plate, cannon, etc. 

Nickel-steel as a rule contains 6 to 7 per cent, nickel. 
With a content of over 5 per cent, the steel possesses the 
most favorable properties of strength, but is also of such 
natural hardness that it can scarcely be worked in the 
cold state. 

MOLYBDENUM, TITANIUM, VANADIUM. 

Molybdenum is seldom alloyed with tool steel because 



CLASSIFICATION OF TOOL-STEEL. 9 

the high price of the metal does not allow of its extensive 
use, and as its action is very similar to that of tungsten the 
same result can be attained with the latter metal. 

Titanium and vanadium are not employed in the manu- 
facture of tool-steel on account of their high price and the 
difficulty in producing varieties of steel alloyed with them. 

Titanium and vanadium steels have been made on a 
small scale for the purpose of testing their properties, and 
titanium has been found to impart special hardness, and 
vanadium special tenacity, to steel. 

^Nevertheless varieties of steel — especially of English 
origin — are brought into commerce under the names of 
molybdenum-steel, titanium-steel, vanadium-steel, but of 
course they do not contain any of these constituents. 



11. 

CLASSIFICATION OF TOOL-STEEL ACCORDING TO 
THE DEGREE OF HARDNESS AND THE PUR- 
POSE FOR WHICH IT IS TO BE USED. 

*^As regards the varieties of tool-steel brought into com- 
merce two groups may be distinguished so far as products 
of crucible steel are concerned, namely : 

a. Tool-steel Avhich acquires its hardness exclusively from 

a content of carbon and does not contain any admix- 
tures which increase the hardness. 

b. Tool-steel, which in addition to carbon, contains ad- 

mixtures increasing the hardness. In practice it is 
generally called special steel, or after the kind of 



Ml TOOL-STEKL. 

admixture — chrome-steel, tungsten-steel, nickel- 
steel, etc. 

The tool-steel brought into commerce is nearly always 
provided with the stamp of the firm and a colored printed 
label. The latter, in addition to the name of the firm and 
trade-mark, contains data regarding the degree of hardness,, 
the principal purposes for which the steel is to be used, and 
the temperature to be employed in forging and hardening. 

In some manufactories of tool-steel the degree of hardness 
is expressed by figures corresponding to the content of car- 
bon, for instance, degree of hardness 7 — containing 0.70 
per cent, carbon — while in others it is expressed in such 
allegorical designations as : very hard, super-hard, extra 
hard, hard-hard, medium hard, tenaciously hard, tenacious, 
very tenacious, soft. In addition to these designations the 
content of carbon in per cent, is occasionally given. 

The color of the paper label is generally so selected that 
the hardest steel is provided with a label of the lightest,, 
and the softest steel with one of the darkest, color. 

The varieties designated special steel, which as a rule are 
alloyed with tungsten or chromium, are in practice pro- 
vided with labels of different text and colors from those of 
ordinary tool-steel. 

While the above-mentioned allegorical designations for 
the degree of hardness of tool-steel are in use in most fac- 
tories, not all of them understand under the same desig- 
nation the same practical degree of hardness according to 
the content of carbon. Thus one factory designates steel 
with 1.2 per cent, of carbon as super-hard, while another 
terms it medium hard or hard, and steel with 0.6 per cent, 
carbon is designated as soft, tenacious and even tenaciously 
hard. 



CLASSIFICATION OF T00L-STP:EL. 11 

Nevertheless in practice, these designations serve their 
purpose, their chief object being to enable the consumer 
to procure steel of the same degree of hardness from the 
same source of supply. In judging the fitness of a quality 
of steel for a definite purpose the percentage of carbon 
alone is by no means decisive. 

It may be accepted as a general rule that for a deter- 
mined purpose a tool-steel may be selected which may be 
the harder (richer in carbon), the freer from injurious ad- 
mixtures, sulphur, copper, phosphorus, etc., it is. 

The higher the percentage of carbon in a steel which for 
a determined purpose may be chosen, the greater will be 
the useful effect which may be expected of a tool made 
therefrom, but the more care must also be bestowed upon 
the treatment of the tool while being manufactured. 

However, in practice, the useful eff'ect of the finished 
tool is not always taken as the standard for judging the 
fitness of a tool-steel. In the majority of cases steel is 
judged according to the manner in which it can be worked 
into finished tools without making special demands on the 
intimate knowledge and attention of the tool-smith, forge- 
man or hardener, and without the requirement of special 
devices for the most important operations in the manu- 
facture of tools, namely, forging, annealing, hardening, 
tempering, etc. 

Soft steel is less exposed to the danger of over-heating 
and burning than hard tool-steel, and by reason of its 
greater toughness, is less liable to crack in hardening. 
Hence it requires less attention in working and conse- 
quently is more largely used in the practice than hard 
steel. This is one of the reasons for the extensive employ- 



12 



TOOL-STEKL. 



ment of soft Bessemer and Martin steels in tlie manufacture 
of tools, even where the advantage of tlie greater useful 
effect of crucible cast-steel, which is used much harder, 
should be appreciated. To be sure this greater useful oifect 
is not alone attained by the employment of harder steel, 
very conscientious and careful work in the manufacture 
of the tools being also required, as well as thoroughly- 
informed and experienced forge-men and hardeners. 

From what has been said in the foregoing, it seems use- 
less to lay down a rule which would be even of general 
value for the degree of hardness to be chosen for deter- 
mined purposes. For this reason the classification of steel 
according to the degree of hardness and the purposes for 
which it is to be employed, as in use in Bismarckhuette, 
and which on an average has proved of practical value, 
will here only be given as follows : 



Degree of liard- 
ness. 



Very hard . 
Hard 



Medium hard 

Tenaciously liard • 

Tough 

Soft 



Average 
per cent, 
of carbon. 



1.5 

1.25 

1.0 

0.85 
0.75 
0.65 



Purposes for whicli Employed. 



For turning and planing knives, drills, turning 

gravers, etc., for very hard materials. 
For ordinary turning and planing knives, rock 

drills, mill picks, knife picks, scrapers, etc., 

and for cutting tools for hard metals. 
For screw-taps, broaches, cutters, tools for 

stamping presses and for various tools used 

by locksmiths and blacksmiths. 
For screw-taps, cutters, broaches, matrices, 

swages, pins, bearings, chisels, gouges, etc. 
For chisels and gouges, shear-blades, drifts, 

springs, hammers, etc. 
For various blacksmith tools, as weld-steel for 

steeling finer tools and larger surfaces, etc. 



SPECIAL STEELS. 

The principal commercial varieties of special steel, the 



CLASSIFICATION OF TOOL-STEEL. 13 

hardness of which has, in addition to carbon, been in- 
creased by a content of tungsten or chromium, are as 
follows : 

Natural tool-steel, also called self-hardening, boreas, 

mushet steel. 
Special turning steel. 
Magnet steel. 

Natural or self-hardened steel in an unhardened state 
possesses such great cutting power and hardness that in 
this state it can be employed for cutting tools which are 
not subjected to shock. 

When slowly cooled from a red heat the hardness of nat- 
ural steel is greater than when rapidly cooled from this 
temperature, and its behavior in hardening is thus the 
reverse from ordinary tool-steel. 

Self-hardened steel has the advantage of retaining its 
hardness when heated, and is therefore suitable for lathe- 
cutters upon hard materials in lathes running at high 
speed, whereby heat is generated, or for taking off a chip 
of extra thickness, etc. Such cutters keep their edges much 
better than cutters of ordinary steel. This property of self- 
hardened steel is due to a higher content of tungsten, man- 
ganese and silicon. The composition of self-hardened steel 
is shown by the analyses given below : 

Carbon. Manganese. Silicon. Tungsten. 

English mushet steel 1.71 1.8 0.81 7.75 

Styrian steel 1.78 1.85 1.01 9.72 

Bismarckhiitte natural steel .. . 2.04 1.78 1.08 9.50 

Very hard special turning steel contains, in addition to 
1 to 1.5 per cent, carbon, 3 to 6 per cent, tungsten, man- 
ganese and silicon in the usual quantities found in other 



14 TOOL-STEEL. 

tool-steel. It contains very seldom a higher percentage 
of manganese or silicon with a smaller content of tungsten, 
as, for instance, the special steel produced by Marsh Bros., 
which with only 1.8 per cent, of tungsten contains 1.8 per 
cent, of manganese. 

All varieties of special steel, the hardness of which is 
considerably increased by a larger content of tungsten, re- 
quire specially careful treatment jn hardening if their 
hardness is to be tlioroughly effective without tlie tool 
succumbing to the correspondingly enormous hardening 
strains and cracking. To insure suitable treatment in 
hardening, such varieties of special steel are generally 
accompanied by special, explicit instructions. 

Magnet steel * has a composition similar to that of special 
steel, and generally contains as large a percentage of tung- 
sten, the latter exerting considerable influence upon the 
improvement of the magnetic properties of the steel. 

Since the cutting power of magnet steel is of secondary 
importance, it is generally given such a chemical composi- 
tion as to make its magnetic properties most effective. 

There are numerous varieties of special steel, the chem- 
ical composition of which does not differ from that of 
ordinary steel. They are generally designated by names 
indicative of the purpose they are to serve, and for which 
they are claimed to afford the greatest efficiency attainable. 

Tool-steel for definite purposes, the cross section of which 

* It may be accepted as a general rule that the coercive power, )'. e., the 
power with which the iiiagnetisni is retained, and the quantity of magnetism 
taken up, are the greater tlie harder the steel is. The admixtures of man- 
ganese and silicon in steel, which can never be entirely avoided, exert an in- 
fluence according to the quantities present. 



CLASSIFICATION OF TOOL-STEEL, 



15 



shows different degrees of hardness, is generally produced 
by welding together iron or mild steel with hard steel in 
casting the crude block. The accompanying sketches, Fig. 
1, show such varieties of steel, the hatched lines represent- 
ing hard steel. 

Fig. 1. 






1 






Such steel is used for a variety of cutting tools, the edges 
of which consist of hard steel and the backing generally of 
iron ; further for safes, calks for horse shoes, etc. 

The variety of tool-steel brought into commerce under 
the name of soft-centred or mild-centred steel is hardest on 
the surface, while the interior is very soft. The transition 
from hard surface to soft interior is a gradual one and 
seldom sharply defined. Such steel is produced by cemen- 
tation of mild steel, carbonization being arrested at a 
definite stage. This mode of production frequently results 
in an unequal material, and for this reason such steel is 
seldom used in practice for the manufacture of tools. It 
is, however, employed to advantage for machine-parts which 
have to be very tough, but portions of the surfaces of which 
have to be harder to protect them against rapid wear, for 
instance, crank pins, dynamo shafts, etc., the bearing por- 
tions of which are hardened while their interior are left 
tough and soft. 



16 TOOL-STEEL. 

III. 

OBSERVATIONS ON THE EXTERNAL APPEAR- 
ANCE OF COMMERCIAL TOOL-STEEL. 

When receiving tool steel, the eye of the consumer is 
involuntarily drawn towards its external condition. So far 
as the quality of the steel is concerned, the most percept- 
ible features in this respect are the appearance of the 
fracture and the cleanness of the surface. 

With steel carefully made defects can seldom be noticed 
by the fracture and surface. 

The surface of steel may show the following defects: 

Scales, the form of which represents a .single line running 
in a curve, or the line may consist of several coherent 
curves. Such scales generally originate from dross on the 
surface of the block which has not been removed, from 
remnants of slag or from skins formed in casting the steel. 
They are more seldom due to faults in forging or rolling. 

Cracks are outlined on the surface of the steel by short 
lines, either singly or in groups, running parallel to the 
longitude of the surface. They are partially concealed 
from view by the layer of oxide covering the steel, but may 
readily be exposed by means of a file. These cracks are 
due to pores which in casting the steel-ingot have been 
formed immediately below the surface. 

Seams are formed by the steel protruding laterally in 
rolling or forging in the swage and by turning down and 
squeezing in the protruded material in the further working 
of it. The seams run always parallel to the longitude of 



EXTERNAL APPEARANCE OF COMMERCIAL TOOL-STEEL. IT 

the steel, generally on two sides or edges of it ; more seldom 
alternately, or on one side only. On rolled steel such 
seams readily escape observation when they are covered 
with a layer of oxide. 

Edge-cracks are cross-rents on the edges which run ver- 
tically to the direction of the length of the steel. They in- 
dicate red-shortness or hot-shortness, or that the steel in 
forging has been strongly overheated (burnt). Such steel 
is of course entirely unfit for the manufacture of tools. 

In the further working of the steel the principal defects 
noticeable on the surface, which have been mentioned 
above, are frequently productive of defective tools because 
cracks formed in hardening originate from them. 

The appearance of the fracture is not decisive as regards 
the quality of unhardened steel, and only within very un- 
certain limits as regards its hardness. 

The structure of soft steel shows a coarse grain, and that 
of hard steel generally a fine grain, the latter being the 
finer the more carbon the steel contains, provided the sur- 
faces of the fractures which are to be compared have been 
produced under the same conditions. 

If the fracture of very soft steel shows a proportionately 
coarse-grained structure and at the same time a dark streak 
towards the edge in which an actual grain can no longer 
be recognized, but an almost fibrous structure, it is indica- 
tive of very soft steel with a very small content of carbon 
— below 0.6 per cent., with less than 0.3 per cent, manga- 
nese. 

If a dark, lustreless streak is noticeable on the fracture of 
hard steel which otherwise shows a fine-grained structure, 
it is indicative of the presence of carbon in graphitic form. 
2 



18 TOOL-STEEL. 

Such steel acquires only an unequal, insufficient degree of 
hardness and always yields bad tools. 

The following defects, if present, may be observed on the 
surfaces of the fractures of tool-steel : 

1. Flaws or blisters, in tlie center, and more seldom, 

towards the edge of the steel. 

When towards the edge of the steel, they are due 
to pores, and when in the centre of the fracture, to 
the pipe. 

2. A spot, generally symmetrically formed, in the centre 

of the steel, which shows a coarser or finer structure 
than the surrounding parts. Such spots are formed 
by liquation on cooling steel freshly cast, and their 
chemical composition differs from that of the sur- 
rounding portions. When the fracture of such steel 
is filed, ground, polished and pickled in acid, spots 
of unequal hardness (unequal chemical composition) 
are outlined as quite sharply defined surfaces of 
different coloration. 

3. When cutting up a bar of steel into the separate parts 

serving for the manufacture of a tool, flaws may 
also be noticed in the centre of the steel. Such 
flaws are only in rare cases attributable to a con- 
tinuation of the pipe, but are more frequently due 
to destructive forging. In forging bar-steel it is 
nearly always worked colder in the centre than 
on the ends, the interior being readily shattered 
thereby. The flaws thus formed seldom extend to 
the surface of the steel, and, therefore, escape detec- 
tion in the works where the steel is produced. The 
defect caused by destructive forging is more fre- 



FRAOTURE OF STEEL. 19 

qiiently found in hard steel and in material of 
small or thin dimensions. 
In most tool-steel works it is sought to avoid the above- 
mentioned defects which can be noticed on the surface and 
fracture of the steel, and the various products are subjected 
to very careful inspection before being shipped to prevent 
defective material from reaching the consumer. 



IV. 

OBSERVATIONS ON THE FRACTUKE OF STEEL, 
WITH REGARD TO THE STRUCTURE IN 
THE HARDENED AND NON- 
HARDENED STATES. 

It requires considerable practice and much experience to 
be able to judge, with any degree of certainty, from the 
appearance of an otherwise faultless fracture, the quality 
and incidentally the hardness of a variety of steel. 

As previously mentioned, the structure of steel becomes 
more fine-grained as the hardness increases. However, 
steel of the same degree of hardness may show an entirely 
different structure if before being broken it has been 
worked in different ways, and after having been worked, 
has been cooled from high temperatures of different de- 
grees. 

Tool-steel which has been heated and then very slowly 
cooled, and the fracture of which has been effected by 
nicking and breaking while in the cold state, shows the 
most coarse-grained structure pertaining to its degree of 
hardness. 



20 tool-stkr:l. 

The appearance of the fracture of unhardened steel as 
brought into commerce is in the main dependent on the 
following conditions : 

1. On the temperature from which tlie steel has been 
cooled before it is broken. 

Changes in shape are much more rapidly effected 
by rolling than by forging, and the steel, when 
allowed to cool, has a much higher temperature. 
For this reason rolled steel has, as a rule, a more 
coarse-grained structure than forged steel. 

The fractures of the two ends of the same bar 
of forged steel show sometimes a different appear- 
ance if, after forging, one-half of the bar has been 
cooled from a lower or higher temperature than the 
other. 

2. On the degree of mechanical manipulation. 

Tool-steel of the same degree of hardness shows a 
finer structure in smaller dimensions and a coarser 
structure in larger dimensions. 

In producing smaller dimensions the loss of heat 
takes place more rapidly, but the change in shape 
requires more powerful working of the steel ; and 
this being finally effected at a lower temperature, 
the fracture shows a fine-grained structure. 

3. On the temperature of the steel before it is worked. 

Steel over-heated in heating for forging or rolling 
acquires an entirely or partially coarse-grained 
structure, which possesses a characteristic bright 
lustre different from the normal color of steel. 

'I'his structure frequently forms a border around 
the edge of the fracture or runs from the edge 



Heat observed in 
a dark room ; 
and its temper- 
ature in ciegrees 
F. 



Bright white 

HEAT. 

The steel emits 
sparks. 
2732°. 



Dull white 

HEAT. 

2192°. 



Bright yellow 
heat. 
2012°. 



Yellow heat. 

1832°. 



Yellow-red 
heat. 
1650°. 



Bright red 
heat. 
1482°. 



Cherry-red 
heat. 
1382°. 



Dark red heat. 
1202°. 



Brown-red 

HEAT. 

1022°. 



(To face page 21.) 



The steel heated to 
the annexed tem- 
perature allows 
alter slowly cool- 
ing of tile follow- 
ing observations on 
the fracture. 



Quite coarse- 
grained, but 
sound and uni- 
form structure. 



The steel heated to the annexed temj 
and then hardened, allows of the foil 
observations: 



Hardness. 



Very coaise crys- 
talline structure 
of a characteristic 
white glistening 
color. 









^ S r 



be c;= = 

V- Ci C3 02 



C o a r s e-g r a i ned 
structure in 
which are dis- 
seminated, espec- 
ially towards the 
edge, coarser 
particles of a 
white lustre. 



J- 

A higher, 
but still 
brittle 
degree 
of hard- 
ness. 



Surface: White color o 
tallic lustre; generally a 
cracks. 

Fr ACTUR E : C a r s e -cr 
structure of a cham 
white glistening color. 

The steel is overheated ti 
degree; eventually also i 



Surface : Dull metallic 
here and there white lu^ 

Fracture: Coarse grain ( 
lustre, with coarser parti< 
white lustre interspei'se 
frequently towards the t|( 

The steel is highly overh: i 



Surface: Dull metallic c 
Fracture: Hard steel 
overheated; soft steelll 
a quite coarse-grained stic 
without the accompanyii 
cations of overheating. 



1 






J 



Surface : Dull metallii 
layers of oxide and sea 
quite completely come o 

Fracture: Fine structu 
velvety lustre, scarcely p 
ble to the naked eye 
somewhat more coarse- li 
from the edge towards th 
In the interior the steel 
hard but tougher than 
surface. 



Superficial 
slight 
h a r d - 
ness, not 
penetrat- 
ing to a 
great 
depth. 



Surface: The layer of ox|; 
incompletely come off. 

Fr.\cture: a narrow hv^n 
fine-grained structtu-e w 
wards the centre passii^ 
abruptly into a core only j;i 
hardened or not at all. f 



I The appearance of , 
! the fracture has \ 
\ s u ffe red very 
I little or no 



change. 



The steel 
does no 
longer 
acquire 
hardness. I 



Surface and fracture have 
no material changes. 



T. IBLE I. 



re( 1 



Pbactical Application of the Annexed Temperatures. 



In 

Welding. 



Welding heat for 
iron- not capable 
of being hard- 
ened. 



Welding heat for 
actual weld-steel. 



In 
Forging. 



Welding heat for 
weldable crucible 
steel of slight 
hardness. 



Welding heat for 
hard crucible steel 
not actually weld- 
able, with the use 
of welding agents. 



In 
Annealing. 



The annexed temper- 
atures must not be 
used in forging 
steel, it being 
spoiled thereby. 



In 
Hardening. 



Forging heat for soft 
steel. 



The annexed degrees 
of temperature must 
not be used in an- 
nealing steel, be- 
cause it would be 
spoiled thereby. 



Forging heat 
hard steel. 



for 



Forging heat for es- 
pecially hard steel. 

Forging heat at 
which steel previ- 
ously overheated, 
almost reacquires 
its normal struc- 
ture. 



Tools hardened at the 
annexed tempera- 
tures are useless in 
consequence of too 
high a degree of 
brittleness, and be- 
come cracks in 
hardening or soon 
afterwards. 



Hard steel forged at 
the annexed tem- 
peratures is readily 
shattered or be- 
comes flawed in tlie 
interior. Every 
kind of steel be- 
comes brittle and 
gets forging strains 
iu consequence of 
which the tool 
readily cracks in 
hardening, if not 
previously an- 
nealed. 



Annealing heat for 
tool steel. When 
the steel has ac- 
quired a uniform 
heat it must especi- 
ally not be exposed 
for a longer time to 
the air, but must be 
slowly cooled with 
exclusion of air, 
otherwise it will be 
spoilt. 



Hardening tempera- 
ture of steel scarcely 
capable of being 
hardened or for 
case-hardening iron. 



Hardening tempera- 
ture for soft tool 
steel. 



Hardening tempera- 
ture of tougli to 
hard steel. Tough 
steel is hardened at 
a brighter red heat; 
harder steel at a 
darker red heat. 



Annealing or hardening at the annexed 
temperatures is without material influence 
upon the hardness of the steel, but of 
great influence as regards its properties of 
strength. 



FRACTURE OF STEEL. 21 

towards the centre of the steel ; and if the steel had 
been over-heated to a higher degree, does not en- 
tirely disappear by subsequent manipulation. 
4. On the manner in which fracture has been effected. 

Steel which has been nicked in the cold state and 
then broken shows a more coarse-grained structure 
than steel which has been nicked in a red-hot state 
and broken after cooling. 

Nicking in a led-hot state is equivalent to a 
mechanical manipulation at a lower temperature, 
and hence the finer structure. 
The appearance of the fracture of hardened steel is de- 
pendent on the following conditions : 

1. On the temperature at which the steel by rapid 
cooling has been hardened. 

Suppose a bar of steel has been heated so that the 
brightest white heat slowly extends from one end to 
the other, passing through a yellow, red, and brown 
heat to hand-warm. Now, if this bar is hardened 
by being quickly quenched in water, the changes in 
the structure of the steel while being heated and the 
influence of the various degrees of heating upon the 
structure, the degree of hardness and the toughness, 
may be recognized by the separate broken portions 
and the appearance of their fractures. 

The higher the temperature at which hardening 
has been effected, the more coarse-grained the struc- 
ture of hardened steel will be. 

The accompanying tables show the influence 
of the various degrees of temperature upon hard- 
ened and unhardened steel, and their general appli- 
cation in practice. 



22 TOOL-STEEL. 

2. On the dimensions of hardened steeh Steel with a 
small cross-section yields up heat more quickly in 
hardening than steel with a large cross-section. It 
is more uniformly hardened throughout, and its 
fracture shows a more uniformly fine-grained struc- 
ture. 

Steel of larger dimensions yields up its interior 
heat but slovvl}^ and hence does not acquire the 
same degree of hardness in the interior as towards 
the surface. The face of the fracture shows in the 
centre a more coarse-grained structure which be- 
comes more fine-grained towards the edges. 
3. The appearance of the fracture in the hardened state 
is dependent on the structure only when the steel 
has been overheated or when it has previously been 
subjected to vigorous mechanical manipulation. In 
the former case the steel in the hardened state shows 
a coarser, and in the latter case, an especially fine, 
structure. 



V. 

PRACTICE OF THE FIRE-TREATMENT OF STEEL. 

In the manufacture of tools repeated heating of the steel 
is in most cases required, partially for the purpose of shap- 
ing (forging), partially for increasing the capacity of being 
worked (annealing), and for hardening and tempering the 
finished tool. 

Shaping can only in a few cases be effected by one heat- 



Tempee 

ATtJRE, 

Degrei 
F. 

Up to 
392°. 



428°. 



446°. 



■ilA' 



491°. 



509°. 1 



527°. 



.■)45<= 



590^= 



617°. 



626°. 



(To fa 



Table II. 



Temper- 

ATURE. 

Degrees 
F. 



Up to 
392°. 



428°. 



446°. 



Temper-color. 



None. 



Bright Yellow, 



Pure Yellow. 



473°. Dark Yellow 



491°. 



509°. 



527°. 



•")45°. 



590^ 



617< 



626= 



Brown Yellow. 



Ked-Brown. 



Purple Rkd. 



Violet. 



Cornflower 
Blue. 



Pale Blue. 



Gray. 



None. 



Use with Tools of 



Hard 



Medium Hard 



Tough 



Steel. 



Letting-down steel at degrees of temperature at which no temper color is produced 
increases its toughness and slightly decreases its hardness, especially if letting-down 
is continued for some time. It can be applied with excellent results in the operation 
of hardening to avoid cracks and to increase the toughness of the steel of all kinds 
of tools. 



For quietly-running tools of great cutting power, 
with the use of iiard steel, chilled castings, etc.; 
also for turning tools, taps, plane-irons, drills, 
gravers, etc. 



For quietly running cut- 
ting tools of compli- 
cated shape: Cutters, 
broaclies, twist drills, 
thread cutting tools, 
turning knives, etc. 

Stone-working tools sub- 
ject to blow and shock: 
Stone drills, charing 
hammers, mill picks, 
knife picks, etc. 



For cutters, broaches, 
twist drills, thread cut- 
ting tools, turning 
knives, as well as for 
tilecutter'schiselsjdies, 
metal saws, punches, 
matrices, drills, pins, 
pivots, steps, etc. 



Turning and planing 
knives for very soft ma- 
terial, such as wood, soft 
metals, bones, etc. 

For cutting stamps, dies, 
punches, stone working 
tools, hammers, lock- 
smith's chisels, mark- 
ing stamps, augers for 
wood, punches, shear 
knives, etc. 



Thread cutting tools for 
iron and soft metals, 
cold chisels, core turn- 
ing tools for wood, 
marking stamps, etc. 



For tools which with ad- 
equate hardness are to 
possess special tough- 
ness: Pins, pivots, steps, 
metal saws, dies, twist 
drills, cutting tools for 
soft materials, such as 
wood, leather, bones, 
copper, brass, file cut- 
tei''s chisels, numbering 
stam})s, punches, mat- 
rices, etc. 



Is never used to advantage 
with hard steel. Use 
less hard steel with the 
choice of a lower temper 
color. 



Shear knives, cold 
punches, hand chisels, 
liot and cold chisels, 
locksmith's chisels, 
marking stamps . 
punches and dies, etc. 



Cutters for wood, punch- 
ing chisels, planing 
knives for paper and 
wood, axes, hatchets, 
scythes, saws, hand 
chisels, cold and hot 
chisels for iron, small 
hammers, milling tools, 
rivet punches, etc. 



Surgical instruments, springs, 
saws, sabres. Cutters for 
j soft wood. 



Same as in the othei 
column. 



. il 



Machine parts which are 
not to possess a high 
degree of hardness, but 
are to be very tough 
and strong. 



Remarks. 



The different ways of application 
for tempering tools given in the an- 
nexed columns are not available with- 
out some qualifications. The choice 
of tlie temper color is dependent: 

1. On the degree of hardening; keenly 
hardened steel requires better tem- 
pering. 

2. On the hardness of the steel. 
Harder steel requires for the same 
object stronger tempering than soft 
steel. 

3. On the condition of the steel as 
regards injurious admixtures. Steel 
which has become brittle in conse- 
quence of injurious admixtures re- 
quires stronger tempering. 

4. On the purpose for which the tool 
is to be used. With an incorrect 
choice of the degree of hardness 
for a certain purpose, poor effi- 
ciency and defects in use can only 
seldom be overcome by higher or 
lower tempering. The choice of 
the temper color depends less on 
the required degree of hardness 
than on the degree of toughness. 
Tools which are to i)ave s|)ecial 
toughness without too high a de- 
gree of hardness are let down twice 
or thi'ee times in succession to tlie 
same temper color. 



(To face page 22.) 



FIRE-TREATMENT OF STEEL. 23 

ing, and in many cases a worn-out tool has repeatedly to 
pass through the above-mentioned operations without its 
quality suffering injury from repeated heating. 

Hence, in the manufacture of tools particular attention 
has to be paid to every operation for which the steel has to 
be heated, and the appliances for this purpose should be 
properly adapted. 

This adaptation should be in accordance with the follow- 
ing principles, which must be strictly observed : 

1. The steel should always be heated so uniformly that 

it is not heated more, either in its entirety or par- 
tially, than is absolutely necessary for the subse- 
quent operation. 

2. Heating should be effected as rapidly as possible 

without bringing the single parts (corners, edges) 
of the steel to a higher heat prior to the body. 

Though simple and self-evident as these principles may 
appear, they are frequently transgressed as regards the 
operation in question itself, as well as in the appliances for 
carrying it out. 

The appliances for heating the steel include in the main 
fire and furnaces, as well as fuel. 

The quantities of fuel and their value are mostly small 
in comparison with the value of the tool to be produced, 
and the essentially greater efficiency of a tool which has 
been carefully made. 

The choice of fuel depends partially on local conditions 
and partially on the manner in which it is to be applied. 
In many cases the heating devices are adapted to the pur- 
pose in view as well as to the fuel at disposal. 

The disadvantages which may result, as far as the qual- 



24 TOOL-STKKL. 

ity of the steel is concerned, from the use of certain fuels 
will now be described, as well as the means necessary to 
successfully avoid them. 

Hard coke, which does not stain the hand, and when 
struck emits a clear sound, is used in the manufacture 
of tools in the open fire as well as in furnaces. The harder 
the coke is, the higher the temi)erature will be, and the 
more air for the combustion of the coke required. 

Hence, in a coke-fire, tool-steel is readily heated too 
rapidly and too much, and the larger the pieces of coke 
the more it is exposed to the action of the blast. These 
are conditions under which the steel may readily become 
overheated, and even burned. 

When no other fuel besides hard coke is available, the 
furnace shown in Fig. 2 should be used for heating the steel. 

For the construction of this furnace take a piece of fire- 
tube, or similar material, about 3^ feet long and IH to 24 
inches in diameter, and provide it at a, b, c with apertures 
to which doors of stout sheet iron are fitted. Place the 
tube thus prepared upon an ordinary brick pavement, line 
it with fire-brick, as shown in the illustration, fix the blast- 
pipe w under the grate, and close the upper portion of the 
brick work with an arch. The cover of the furnace is pro- 
vided with an aperture 4| to inches in diameter, in 
which is fitted a smoke-pipe 3J to 13 feet high and pro- 
vided with a damper for regulating the draught. 

The fuel is introduced through the doors a, b. The door 
b is the actual working door, the door a serving for passing 
through long bars, which are to be heated in the centre for 
the purpose of dividing them. 

The coke burning in the space *S' heats the working space 



FIKE-TREATMEXT OF STEEL 



25 



A, ill which the tool, held by means of tongs or resting 
upon a grate-like supiJOit, is heated. With a smoke-pipe 
of sufficient height, a blast-pipe is not actually required, 
since the free draught is sufficient to produce the high and 



Fig. 2. 




uniform heat required in x\. The suitable degree of tem- 
perature can, within a certain limit, be effected by regulat- 
ing the draught. 

Smith-coal or forge-coal. The variety of coal thus desig- 
nated cakes readily, swelling up thereby, and is most 
frequently used for open forge-fires. However, it contains 



26 TOOL-STEEL. 

sometimes a higli percentage of sulphur, the presence of 
which may spoil tool-steel heated in such fire. To remove 
a content of sulphur, allow the coal to burn thoroughly 
through until no more smoke is evolved, repeating the 
operation every time fresh fuel is added. 

The effect produced by a content of sulphur in the coal 
upon the steel heated therein is as follows: 

At a high temperature sulphur has a great tendency 
towards combining with iron. This combination cannot 
be hardened and causes the formation of so-called soft spots 
in the steel, /. e., spots of greater or smaller extent on the 
surface of the steel, which acquire no hardness whatever in 
hardening the tool. 

When smith-coal in an open fire is ignited it readily 
cakes on the surface to a coherent cover underneath which 
combustion takes place at a very high temperature. If 
this cover is not broken up such fire may burn "hollow." 
If steel for the purpose of heating is brought into the 
hollow space, it is heated in immediate contact with the 
blast and is " burnt " at a temperature which, with the 
exclusion of the oxygen of the air, would not be high 
enough to spoil it. In heating tool-steel in an open fire it 
is, therefore, necessary to prevent the coal from forming a 
solid cover. The development of a less intense heat in a 
fire frequently loo.sened is rather an advantage in heating 
steel. 

Coke dust. Coke in minute fragments or reduced to dust 
is not suitable for use in an open fire, because the blast 
cannot with sufficient ease penetrate between the inter- 
spaces of the fuel to induce sufficiently extensive combus- 
tion. Such coke may be used mixed with smith-coal, it 
readily caking together with it. 



FIRE-TKEATMENT OF STEEL. 27 

The highest degree of heat developed in an open fire 
is immediately in front of the tuyere, and in the zone sur- 
rounding it, within which the blast, scattered by striking 
the coal and weakened in force, just maintains the coal in 
full glow, is found the degree of heat lequired for forging 
and hardening. This heat, however, decreases too rapidly 
in intensity towards the surface of the fuel put on. 

The heat developed in the middle zone is, of course, 
not uniform, it being more intense towards the centre of 
the fire and less so towards the surface. For this reason it 
will be difficult to heat articles to a uniform heat in this 
zone when it is narrow, /. e., when but a small quantity of 
fuel has been put on. The more fuel is put on, the greater 
will be the width of the heating zone which can be 
utilized for forging and hardening, and the larger in size 
the articles may be which can be heated in it. It is 
extremely difficult to heat in an open fire to a uniform 
temperature pieces of especially large size, such as anvils, 
hammer-blocks, swages, etc., it being almost impossible to 
avoid roasting the steel for several hours. Generally it is 
also partially over-heated, while some portions are insuf- 
ficiently heated. In such cases the operation may be 
essentially facilitated by allowing the blast to enter 
through two tuyeres arranged parallel at a distance of 
80 to 200 inches from each other. The tool imbedded in 
the space between the nozzles then receives an adequate 
supplj' of heat, and needs to be turned less frequently. 

When long, thin articles, for instance screw-augers, 
broaches, shear blades, cutters, etc., are to be heated to a 
uniform temperature, even skilled forgemen encounter 
many difficulties on account of the heat not being uni- 



28 



TOOL-SJTEKL 



formly distributed in I he open fire. The corners and edges 
of the tool are readily overheated, and subsequently in 
hardening break ol!'. '\l\v tool, as a rule, is also not uni- 
formly heated, one end or the centre showing a somewhat 



KiG. 8. 




brighter heat than the other portions. In this case the 
open fire can, with small expense, be readily converted into 
a provisional furnace as shown in Figs. 3 and 4. 

Set up bricks, in tiie manner shown in the illustration 



Fig. 4. 




(Fig. 3), around the l)last aperture so that an opening is 
left at m for loosening the fuel A'. By laying a flat piece of 
iron across, an ajierture is made at A, and after putting on 



FIRE-TREATMENT OF STEEL. 29 

the fuel, the structure is closed with a sheet-iron cover, 
which may be provided with a piece of stove-pipe for a 
chimney. By placing a few iron rods in the working aper- 
ture A, a grate may be made upon which the steel is heated 
without coming in contact with the fuel. During the pro- 
cess of heating, the aperture A is to be closed by a strip of 
sheet-iron placed upon the somewhat projecting grate-bars. 
In a provisional furnace thus arranged, thin, long tools 
are readily and well heated to a uniform temperature, 
especially with the use of charcoal as fuel. 

For longer articles it will be necessary to arrange inside 
the heating space two tuyeres alongside each other and 
brick them over. 

Unequal heating or over-heating of some teeth is atti 
especially disagreeable feature in heating cutters, and can- 
not always be prevented even with the greatest care. 
However, large cutters are scarcely ever hardened from an 
open fire, and when it is done it is at the risk of the expen- 
sive tool. 

Small cutters, punches, etc., as well as small tools in 
general, which are to be hardened all over, can be safely 
heated in a muffle built in the open fire as shown in 
Fig. 4. 

Construct from old sheet-iron a pot of a size adapted to 
the articles to be heated and line it with clay mixed with 
cow-hair. Build up bricks around the tuyere and arrange 
the muffle as shown in Fig. 4. The back portion of the 
muffle is placed upon a piece of iron coated with clay 
which rests upon the bricks or upon a piece of brick cut so 
that the blast is divided or diverted into two lateral 
currents. 



^0 TOOL-STEKL. 

The mouth of the muffle is closed by a piece of sheet-iron 
b and the top of the furnace by a sheet-iron plate d. 

It is of great advantage if the muffle M can be fixed be- 
tween two tuyeres. The fuel is introduced from the top, 
the cover d being removed for that purpose. An aperture 
for loosening the fire is provided on the side. Of course 
the articles to be heated must not be brought into the 
muffle before the interior of the latter has acquired a suit- 
able uniform temperature. 

The devices for open fires shown in Figs. 3 and 4 are 
practicable with coke or charcoal, but not with coal. If 
-coal has to be used, one of the reverberatory furnaces to be 
described later on may be employed for uniformly heating 
large pieces of steel or tools made therefrom. 

Mild soft coke, such as is formed on the grate by the 
<;ombustion of caking coal, gas-house coke in small pieces, 
etc., which are of a dark color, stain the hand, crumble 
readily, and when struck do not emit a clear sound, are not 
suitable for forging and hardening from open fires. Tools 
which come only partially in contact with the fire and the 
manufacture of which is simple and rapidly effected, such 
as hand and cross-cut chisels, pointed chisels, drills, ham- 
mers, etc., can, without hesitation, be forged and hardened 
from open fires with such coke. However, for all open 
fires, charcoal is without doubt the most suitable fuel. It 
readily yields to a greater extent the required degrees of 
temperature without a more abundant application of blast, 
and never contains foreign admixtures injurious to tool- 
steel. Hence charcoal should be exclusively used as fuel 
when tools of a finer quality are to be forged or hardened 
from an open fire, or when steel of special hardness, and 



FIKE-TKEATMENT OF STEEL. 31 

hence more sensitive to fire, is to be subjected to these 
operations. 

The great advantage of the use of charcoal for open fires 
is due to its purity and ready combustibihty, and further 
to the fact that the degrees of temperature developed in the 
fire can be more readily observed from the exterior than 
with the use of any other fuel. 

The great combustibility of charcoal allows of the use 
of the smallest quantities of blast, and hence greater protec- 
tion against injurious effects to the steel is afforded. The 
action of the blast upon tool-steel or the finished tool pro- 
duced from it, is the more injurious the higher the tem- 
perature at which it takes place, and the longer it lasts. 

The disadvantages resulting from such action may be 
stated as follows : 

1. The steel oxidizes on the surface and sinter is 
formed, and where oxidation has penetrated more 
deeply uneven spots result, so that the steel, espec- 
ially in finished tools, presents a bad appearance, 
the smooth surface having been destroyed. 

2. The oxygen of the blast readily withdraws from the 
surface of the hot steel, especially on the edges and 
corners, a portion of the carbon, the steel losing 
thereb}^ considerably in hardness and cutting power. 

3. "When the temperature produced in the open fire is 
high and a great quantity of blast is present, the 
oxygen of the latter may not only combine with the 
iron and carbon on the surface of the steel, but may 
also penetrate more deeply into the latter, and by 
forming oxides with the iron, manganese and silicon 
of the steel cause a severance of the structure of the 



32 TOOL-STEEL. 

latter. 8uch .steel is burnt and shows on the edges 
cracks of various de})ths. 

In the subsequent forging, such steel crumbles on the 
places where the cracks are, and also in hardening the steel 
cracks. There is no way of protecting the steel from the 
action of the blast in an open fire. Such protection must 
be given by the mode of working, which should be as de- 
scribed below : 

Heat the cold tool-steel or the finished tool by placing it 
upon the surface of the fuel, turning it frequently, and 
then push it into the })ortion of the fire showing the lowest 
degree of heat, hence near the circumference. Allow the 
steel to remain here until it shows a uniform dark-red heat, 
and then push it into the hotter zone towards the centre 
of the fire. To be sure, in this place the blast strikes the 
steel, but the latter having been preparatively heated, the 
action of the blast produces but little effect, except when 
the pieces are of .such large dimensions as to prevent rapid 
heating. 

If the effect of the blast is to be weakened, the current of 
air is reduced by placing in front of the nozzle irregularly- 
formed fragments of fire-brick, or the steel is protected by 
pieces of sheet iron arranged between the nozzle and the 
steel. In the latter case it is necessary first to put on a 
large quantity of fuel and bring it into a red heat. The 
attacks of the air upon the surface of the steel may be 
lessened by dipping the steel before heating in milk of 
lime or clay water (1 lb. of clay to 1 quart of water thor- 
oughly stirred together). 

Although oj)en fires are much used and are very con- 
venient for most purposes in the maimfacture of tools, their 



FIRE-TREATMENT OF STEEL. 66 

disadvantages make themselves very much felt in the pro- 
duction and hardening of large complicated tools, and in the 
manufacture of implements in large quantities. 

When a large number of tools, for instance, chisels, 
drills, picks, etc., are to be made or to be repaired, a dozen 
of them are at one time put in the fire with the intention 
of preparatively heating them, but the result is that they 
are not uniformly heated, they being partially overheated 
and even burnt. Such tools will in use prove not uniform 
and in consequence there will be loss of steel, as well as 
but slight efficiency. 

Hence in factories where these causes have been recog- 
nized, it has, as a rule, been endeavored to arrange the 
heating devices so that the defects and imperfections 
due to the heating of the steel are in the main avoided. 
By such devices the strain on the tool-smith is relieved and 
limited to what is most essential, and fewer demands are 
made on his skill. Beside, as has been frequently men- 
tioned, the efficiency of a tool carefull}' made is greater 
and consequently there is a saving in material and wages. 
The greater expense caused by the selection of better de- 
vices for forging and hardening are rapidly and fully made 
up by what is saved in wages. 

Before entering into a discussion of the furnaces or fires 
to be used in separate cases, the great importance, especi- 
ally in hardening, of the influence of light in judging the 
degree of temperature of the steel may here be referred to. 

If a bar of steel, such as has been described on p. 21, be 

heated, the degrees of heat mentioned in the table facing 

p. 21 can be observed on it. These observations are based 

upon the purely subjective perception of the observer, ac- 

3 



34 TOOL-STEEL. 

cording to the relation between tlic heat and surrounding 
light. The heat of the same bar of steel will in absolute 
darkness present a different picture from that in dispersed 
day-light or in bright sunshine. What in the first case 
seemed to be bright red, appears cherry-red in the second 
case, and dark red in sunshine. By a changing light the 
eye is dazzled and becomes uncertain in judging the de- 
grees of temperature. 

B}' bearing in mind that the degrees of temperature to 
be used in forging, and especially in hardening, lie within 
very narrow limits and must be exclusively measured by 
the eye of the forge-man or hardener, it will be readily 
understood that not too much should be expected from 
these artisans if forced to work in a light room or in a 
much changing light. The advantage afforded to the 
workmen in this respect is to the interest of the consumer 
of the tools made by them. 

Such advantage can readily be afforded by locating the 
devices for forging and hardening tools in the portion of 
the works which, for want of light, are not suitable for 
other purposes, or if this cannot be done, to prevent the 
entrance of a bright and changing light through the 
windows by providing them with a coat of paint, or 
curtains, etc. 

As previously mentioned, heating the steel in an open 
fire has many drawbacks, which mainly result from the 
uneven temperature produced, the direct contact of the 
steel with the fuel, and from the blast. To avoid these 
drawbacks or to weaken their effect, furnaces are constructed 
in which the steel can come in contact only with the heated 
combustion-gases of the fuel, but not with the fuel itself or 
the blast. 



FIRE-TREATMENT OF STEEL. 35 

As regards their arrangement, the different kinds of 
furnaces are constructed alike and are chiefly intended for 
fuels yielding no actual flame. The furnace previously 
described and illustrated (Fig. 2) is the most simple type. 

The low degree of temperature which must be produced 
in such furnaces for heating tool-steel allows in most cases 
of their being kept in operation without the use of blast if 
a chimney of sufficient height — 10 to 13 feet — is provided. 
One chimney may be used in common for several furnaces. 

The dimensions of the furnaces described below are calcu- 
lated for heating articles of medium size. They may be 
built larger or smaller according to the purpose they are to 
serve, and the dimensions must then be determined in pro- 
portion to the measurements given in the illustrations.* 

Fig. 5 shows a furnace to be operated with coke, though 
a mixture of coke and smith-coal free from sulphur may 
also be used. 

The furnace is built of fire brick and consists, commenc- 
ing from below, of the ash-pit C, the grate r, the belly k, the 
feeding funnel 31, and the working space A, the latter being 
all around provided with a ledge which serves for resting 
upon supports, articles which are to be heated without being 
held by tongs. The working space is terminated by a 
small vault provided with two to four symmetrically 
arranged apertures c d. These apertures are accessible by 
means of a door at 31. They serve chiefly for the purpose 
of eflFecting a uniform distribution of temperature in the 
working space A, and for this purpose can be partially or 

*The measurements given in the illustrations refer to centimeters — 1 centi- 
metre = 0.394 inch. A comparative table of centimetres and inches will be 
found on the end of the appendix. 



36 



TOOL-STEEL. 



entirely closed by the covers a b. The top of the furnace is 
closed by the arch 0, which carries the chimney E. If con- 



Fi(i. 5. 




nection is to be made with another chimney or with one 
used in common for several furnaces, the furnace-gases are 



FIRE-TREATMENT OF STEEL. 37 

conducted into it through the space L, by a flue branching 
ofif sideways. 

To facilitate handling the tool to be held in the furnace, 
a table T\s placed in front of the working-hole P. Both P 
and the ash-pit C are to be provided with well-fitting sheet 
iron doors. The brick work of the furnace is held together 
by clamps and bolts as shown in the illustration. For 
regulating the draught the chimney-flue is provided with a 
special damper or the chimney itself with a movable cover. 
The heating of such furnaces requires from one to two 
hours according to their size, and is continued until the in- 
terior of the working space A, as well as its walls, shows 
a uniform bright red heat. The articles to be heated 
may now be introduced, the following general rules 
being observed. As the temperature rises considerably 
while the furnace is in operation, work should be com- 
menced with smaller pieces which are most readily heated 
and more exposed to the danger of over-heating, and then 
pieces of larger dimensions may be gradually taken in 
hand. The heat which is given out by the glowing fuel 
being greater than that radiated from the furnace walls, the 
articles held in the furnace are heated more on one side 
and must therefore be frequently turned. When articles in 
a cold state are introduced, fresh fuel should at the same 
time be supplied, the higher heat of the furnace being 
thereby slightly modified, and with the use of smith-coal 
and coke mixed, the sooting flame developed affords some 
protection against over-heating and oxidation of the edges 
and corners of the steel. The tool-steel to be heated is 
either directly held wnth forge-tongs — the latter resting 
upon the working table T — or is laid upon a grate-like sup- 



38 



TOOL-STEEL. 



port. Small tools which are to be heated in quantities at a 

a time may be brought into the furnace upon a sheet-iron 

support by which they are protected from the direct heat of 

the fuel. 

Fig. 0. 




Fig. 6 shows a furnace of the same system as Fig. 5, but 
which is operated with charcoal. The only diiference is in 
the arrangement of the door for the introduction of the fuel, 




it being placed somewhat higher to avoid useless consump- 
tion of charcoal by combustion inside of the filling-box. 



FIRK-TKEATMENT OF STEEL. 



39 



Fig. 7 shows the same furnace illustrated by Fig. 5, but 
to save iron parts the filling-box and working table are of 
brick work. 

Fig. 8 shows a furnace for heating long articles, for 
instance long shear-knives, saws, etc., for forging and 
chiefly for hardening. 

The regulating apertures, c d, and their covers, a b, with 

Fk;. S. 




which all the furnaces are provided, as well as the chimney- 
damper, are of special importance for operating this fur- 
nace. By opening or closing the damper the draught in 
the furnace, and thereby the temperature in it, is increased 
or decreased, and by partly closing the apertures c d, the 
heat in separate parts of the furnace may be raised or low- 
ered. Thus by closing the apertures c d in the left half of 



40 



TOOL-STEEL. 



the furnace (Fig. 8), the heat is lowered in this portion 
and raised in the right lialf. 

If the previously-described furnaces are to be fitted for 
coal, or if, with the use of hard coke, the articles to be 
heated are to be protected from a possible contact with the 
sharp-pointed flame developed thereby, the construction is 
as shown in Fig. 9. 

Fig. 9. 




The coal or coke is here burnt under the arch U, the 
working space A being heated through the two slits Z. 
Thus the steel to be heated does not come in direct contact 
with the fire or the combustion-gases of the furnace, heat- 
ing being effected under conditions similar to those in a 
muffle. 

By constructing, about 10 to 10 inches above the arch U, 
another arch accessible by the door T, as shown in Fig. 10, 
the hearth thus obtained may be used for preparatory heat- 
ing. When room is wanting, the use of such furnaces can 
be recommended especially for continuous work in forging 
and hardening articles on a large scale, for instance, in 



FIRE-TREATMENT OF STEEL. 



41 



forging balls, files, shears, knives, etc., or in hardening 
calks for horse-shoes, parts of bicycles, etc. 

By placing a muffle of iron or clay upon the arch U in 
Fig. 9, or two muffles, one above the other, as shown in 
Fig. 11, this furnace is converted into a regular muffle- 
furnace, the upper muffle serving for preparatory heating. 
In the muffle-furnace the steel is exclusively heated by the 
heat radiating from the sides of the muffle. However, it 
must not be supposed that tool-steel cannot be overheated 



Fig. 10. 



Fig. 11. 





in the muffle ; on the contrary, this is very easily done if 
due care is not observed. When a muffle furnace has been 
in operation for some time, so that the walls of the furnace 
and the muffle are finally heated throughout to a high 
degree, the heating of the steel is also effected at a higher 
temperature than permissible, and the steel is overheated, 
or at least the projecting corners and edges. 

The interior of the muffle receives heat from every por- 



42 



TOOL-STEJiL. 



tion of the walls, but the greatest heat from the portions 
nearest to the fire-place, therefore from the bottom of the 
muffle, or from the bottom and a side wall. Now if the 
steel to be heated is brought directly in contact with the 
walls of the muffle, the portions touching the walls will 
acquire a higher temperature than the rest and may readily 
be overheated. Hence, the steel is placed upon supports — 
iron rods, or still better, cut pieces of fire-brick — so that it 
does not come in direct contact with the walls of the muffle 
and lies as nearly as possible in the centre. Uniform heat- 

FiG. 12. 




•Air PaaaaS* 



ing is promoted b}^ frequently turning the steel. To pre- 
vent the access of air, the mouth of the muffle should be 
closed as tightly as possible by a door. Iron doors being 
readily warped by the heat, are not as good for this pur- 
pose as sliding doors of chamotte. If an iron door is used 
it should be provided in the centre with a looking-hole, 
w^hich can be closed, for observing the temperature pre- 
vailing in the muffle ; the looking-hole in the chamotte 
door is tightly closed with isinglass. 

Fig. 12 shows a muffle-furnace to be worked with char- 



FIRE-TREATMENT OF STEEL. 



43: 



coal. It serves for continuous heating of band-steel for 
forging, hardening and eventually for tempering. 

Muffle-furnaces, the muffles of which are heated by gas,, 
are very cleanly, and easily attended. Fig. 13 represents- 
such a furnace. The muffle, M, sits in an iron box, K, 
which is lined with chamotte. Underneath the muffle lies 
a heating pipe provided with a large number of holes ar- 
ranged in several rows, and connected by means of a pipe 
with a small blower, ]^. The latter running at a high 
speed sucks gas from a gas-conduit with which it is con- 

FiG. 13. 




nected, mixes the gas wdth air and conducts the mixture to 
the heating pipe. The flame developed plays around the 
muffle and rapidly heats it to a uniform temperature, 
which by regulating the flow of gas can be readily raised 
or lowered. 

Muffles of refractory clay must be heated very slowly 
and carefully, otherwise they may crack. Should cracks 
nevertheless be formed they may be repaired with a paste 
consisting of 4 parts graphite and 1 part clay. 

The above-described furnaces are much used in prac- 
tice, and when properl}'' attended always prove satisfactory. 



44 



TOOL-STEEL. 



The cost of construction is not great, so that their use may 
be especially recommended in works for hardening expen- 
sive tools where the latter are still heated in the open 
forge-fire. 

Although very seldom used for hardening, a reverbera- 
tory furnace is to be preferred to a larger number of forge- 
fires for continuous forging operations on tool steel. 

Fig. 14 shows an ordinary forging reverberatory furnace 



Fifi. 14. 




for heating with coal or lignite. It is provided on each 
side with two working doors and is, therefore, suitable for 
supplying several working places. Combustion is pro- 
moted by a blast-pipe terminating below the grate. 

Fig. 15 shows the same furnace, the only difference being 



FIRE-TREATMENT OF STEEL. 



45 



that combustion of the coal is effected upon a step-grate 
with free draught. 

Fig. 15. 





^^S>5^"S;v^''^5^^^^-$55^ 



Fig. 16 shows a small reverbatory furnace such as is used 
for forging, and also for hardening operations on a small 
scale. 

In case room is wanting, and also for small forging opera- 

FiG. 16. 






tions, the reverberatory furnace, Fig. 17, with two hearths 
may be used, the upper hearth serving for preparatory 
heating of the articles. 



46 



TOOL-STEEL. 



Fig. 17. 




Fig. 18. 




FORGING AN1> HARDENING REVERBERATORY FURNACE. 



FIRE-TREATMENT OF STEEL. 



47 



It must be borne in mind that the heat in a reverbatory 
furnace is not uniform, it being greater towards the fire- 
place and less intense near the working doors. Hence the 
steel is first brought into the colder portion of the furnace 
and then slowly pushed towards the hotter portions. 

Articles to be heated for hardening are brought into the 
portion of the reverberatory furnace which shows the tem- 
perature to be used. To avoid contact with the highly heated 
bottom of the hearth, the articles are placed upon small iron 

Vui. 19. 




rods or pieces of fire brick, and they are protected from the 
■direct action of the flame by placing a piece of sheet-iron 
bent at a right angle in front of them. 

Fig. 18 shows a small reverberatory furnace with step- 
grate and two hearths, one above the other. 

Fig. 19 illustrates a reverberatory furnace with a fire- 
place patented by Gasteiger, of Vienna. It has to some 
extent been introduced in practice on account of its great 
economy in the consumption of fuel. Its construction is 
according to the following principles : 



48 



TOOL-STEEL. 



The coal is piled upon the solid bottom, B, and gasified. 
The gases generated are highly heated by passing over the 
glowing coke upon the grate, B, and meeting the air, L, 
which enters from the sides, are burned in the space A. 

The heat thus produced is intensified by water-gas, which 
is generated by steam evolved from a vessel filled with 
water which is fixed beneath the grate, the steam passing 
through the layer of glowing coke upon the grate R. 

Fig. 20. 




Fig. 20 shows a reverberatory furnace with muflie which 
is extensively used for hardening and annealing. 



VI. 



APPLIANCES FOR ANNEALING STEEL. 

As has been mentioned in a previous chapter, the struc- 
ture of tool-steel is profoundly afi'ected by mechanical work- 
ing, the grain being finer the more vigorously the steel has 
been worked and the lower the temperature at which the 
work has been done. 



APPLIANCES FOR ANNEALING STEEL. 4^ 

Together with this alteration in the structure of the steel 
its properties of strength also undergo a change, the density 
being increased, the natural hardness enhanced and the 
capability of being worked decreased. 

When in forging tool-steel, some portions of it are sub- 
jected to more vigorous mechanical working than others, 
and some portions remain almost untouched, the tool made 
from such steel showing in these places different degrees of 
strength as well as a different structure, and is said to have 
forging strains. In the further manipulation of such tool it 
works very unevenly and generally cracks in the subse- 
quent hardening. 

To take these strains out of the forged tools or to im- 
prove the capacity of crude steel for being worked, they are 
annealed before being worked. 

In annealing tool-steel the same attention and care must 
be observed as in all other heating operations. 

The following general rule applies to annealing : 

The steel should be heated as slowly and uniformly as 
possible to a cherry-red heat and kept at this temperature 
until it may be supposed to have acquired a uniform heat 
throughout. It should then be protected against too rapid 
a loss of heat and allowed slowly to cool. 

When, in annealing, tool-steel is exposed to the action of 
the air it becomes coated wnth a layer of oxide which fre- 
quently penetrates to some depth. The steel may even lose 
carbon on the surface, the decarbonized places acquiring no 
longer a sufficient degree of hardness, and at a high tem- 
perature the steel may readily be overheated and burnt. 

Hence to protect tool-steel from the action of the air it is 
frequently annealed in vessels. Overheating in annealing 
4 



50 TOOL-STKKL. 

can only be prevented by scrupulous observation of the 
temperature. 

Regarding the practical execution of annealing the fol- 
lowing hints may be given : 

Single tools or pieces of steel maj' be annealed in any 
of the furnaces previously described. When heating has 
progressed so far that the articles show a uniform red heat, 
they are imbedded in charcoal so as to be comjiletely 
covered, and allowed slowly to cool. For annealing articles 
of steel of special hardness sheet-iron vessels, or cast-iron 
boxes especially made for this purpose are used. The 
articles are packed in the boxes between thoroughly burned 
charcoal, horn shavings, iron shavings free from rust, and 
the like. The covers of the boxes and any cracks are luted 
with clay, and the boxes are then heated, the same precau- 
tions as with steel not packed being observed. When suffi- 
ciently heated the boxes are covered with charcoal and 
allowed slowly to cool. The annealed articles should be 
taken from the protecting covering only when thoroughly 
cold. 

For annealing larger quantities of tool-steel or manufac- 
tured articles, it is advisable, especially if the operation is 
to be frequently repeated, to construct special annealing 
furnaces. 

Fig. 21 shows an annealing furnace for forged pieces, for 
instance cutters, files, swages, parts of bicycles, etc., or for 
tool-steel in short pieces. Wood and peat are chiefiy used 
as fuel. Fuels yielding a quick heat should not be em- 
ployed. 

The pieces of steel or the articles are piled upon the 
hearth-bottom so that they are at a distance of a few centi- 



APPLIANCES FOR ANNEALING STEEL. 



51 



metres from the openings i)t m m ; in no case should they 
extend beyond them. The working door is then closed or 




the door-opening bricked up with fire brick, the joints 
being thoroughly filled up with clay. For observing the 



52 



TOOL-STEEL. 



temperature in the furnace looking-holes furnished with 
slides are arranged in the door and side walls. 

The furnace is first heated with small quantities of fuel, 
firing being increased as the temperature rises until the 
steel shows throughout a uniform, not too bright, cherry-red 
heat. This temperature is attained in four to eight hours, 
according to the capacity of the furnace. All the flues 
serving for regulating the work of the furnace are now 
closed, as well as the chimney-damper and the doors, and 
cracks through which air might penetrate into the furnace 
are filled up with clay. The furnace is then allowed to cool 
slowly, which requires 48 to 72 hours. 

Tool-steel thus annealed is of a very uniform, soft quality. 



Fig. 22. 





The same process of operating is to be observed in anneal- 
ing steel in any of the furnaces previously described. 

The furnace, Fig. 21, may also be used for annealing 
steel in an annealing pot or in annealing boxes, the latter 
when filled being placed upon the hearth-bottom and 
heated in exactly the same manner as above described. In 
this case coal may also be used as fuel. 

The mode of arrangement will be seen from Figs. 21 
and 22. 



ArPLIANCES FOR ANNEALING STEEL. 



53 



Fig. 23 shows a furnace with a large anneahng pot, and 
Fig. 24, one with a larger number of smaller annealing 
pots. 



Fig. 23. 




Regarding these furnaces, it may be mentioned that the 
annealing pots may readily be unevenly heated by the 
surrounding flame, in consequence of which the articles 



Fi(i. 24. 




H '"^ 




I. m 


&■■■ 



will be partially overheated, and in the subsequent hard- 
ening yield much waste. However, by very slow heating 
and constant attention this trouble can be avoided. 



54 



T()<)l.->TKl':i, 



For the control ot the result of the aniu'iiling operation, 
small rods of steel — waste or ends of the same quality of 



OfOt. 

r 



§ 




steel — are added to the articles to be annealed and placed 
in the parts of the furnace or annealing pots where over- 



APPLIANCES FOR HARDENING STEEL. 55 

heating may readily take place. When annealing is fin- 
ished, the rods are broken, and by comparing the resulting 
fracture with that of crude steel, a conclusion may be 
drawn as to the temperature attained in the annealing 
furnace. 

Fig. 25 shows an annealing furnace for annealing long 
articles, of the same system as that represented by Fig. 20. 



VII. 

APPLIANCES FOR HARDENING STEEL. 

The various furnaces shown in Figs. 2 to 19 inclusive 
serve aJso for heating steel for hardening. 

In no other operation in the manufacture of tools is 
thoroughly uniform heating of such importance as in hard- 
ening. The slightest error committed here causes damage 
which cannot be repaired. 

Great care should therefore be exercised in the selection 
of furnaces for hardening, since in case the tool is spoiled, 
there is the additional loss of the cost of producing it. 

Unfortunately there are no perfect appliances by means 
of which reliable heating of the tool can be automatically 
effected, the success of the operation depending in this re- 
spect always on the experience and attention of the hardener. 

Imperfect heating appliances require closer attention 
and the observance of numerous rules, which soon tires the 
hardener, and many contingencies arise, the result being 
defective, or entirely useless, tools. Hence appliances 



56 TOOL-STEEL. 

should be provided which do not re(iuire such close atten- 
tion as to make too great a demand on the skill of the 
hardener. 

In reference to the choice of suitable a})p]iances, the 
following hints may here be given : 

If for hardening tools no other contrivance than an open 
fire is available, charcoal should be exclusively used for 
heating, even if it is thought that for momentary use other 
fuel might answer. The result of a change of fuel in favor 
of charcoal will in a short time show itself in the better 
quality, greater uniformity and longer endurance of the 
finished tool. 

The devices shown in Figs. 3 and 4 may in many 
cases be employed with good results, for instance, for occas- 
ionally hardening fine tools, such as iwist drills, broaches, 
cutters, etc. 

By reason of their simple construction and their small 
cost, the furnaces, Figs. 5 to 7 inclusive, may be especially 
recommended for hardening all kinds of tools. With the 
use of charcoal as fuel, hardening is readily executed and 
without great danger even for the most complicated tools. 

The furnace, Fig. 8, should not be wanting in a work- 
shop where long articles, especially shear-knives, are hard- 
ened. 

The various muffle furnaces previously described and 
illustrated are of all the furnaces best adapted for harden- 
ing, and offer the further advantage that fuel may be em- 
ployed, the use of which in other furnaces might be injuri- 
ous to the steel. 

Although in the muffle furnace the tool does not come in 
direct contact with the fuel or its gases, the access of air to 



APPLIANCES FOR HARDENING STEEL. 



57 



it cannot be entirely avoided. Besides, by tlie tool coming 
in direct contact with the walls of the muffle, it may be un- 
evenly heated, and hence still safer methods are in many 
cases desirable. The tools to be hardened are then heated 
so that the air is absolutely excluded, either, 

1. In a bath of molten metal, or, 

2. In a bath of fused salts of a determined melting tem- 
perature. 

Before entering into the further discussion of these 
methods, it may be mentioned that in a melted mass tools 
may also be heated too high as well as too low. The mere 
heating in it offers no guarantee against the above-men- 
tioned defects, if the melted mass itself has been heated too 
high or not uniformly. It can just as readily be over- 
heated as the wall of the muffle or a piece of steel, and its 
being in a fluid state does not prevent unequal heating, just 



Fig. 26. 





the same as with water which in a vessel may be brought 
to boiling on the surface without raising the heat lower 
down. 



58 



TOOL-STEEL. 



Fig. 27. 




The metals or salts are melted in a cast-iron crucible,. 

generally of a round cross-section, which is built in a 

furnace as shown in Fig. 2(). The crucible is heated with 

coke yielding a mild heat, or still better, with charcoal. 

Fig. 27 shows a furnace which may be operated with 

wood or coal, and also with 
lignite. 

Without the use of a pyro- 
meter, the temperature of the 
melted mass is controlled with 
difficulty, and can only be judged 
by the glow of the article heated 
in it. A pyrometer is also of great 
service for an annealing furnace. 
Of the metals in a fluid state which serve for heating 
steel, refined lead without any additions is mostly used. 
Since lead melts at 637° F., and must be superheated to 
about 1382° F. in order to attain the required hardening 
temperature, it is exposed to strong oxidation on the sur- 
face, and the loss by evaporation is very large. To decrease 
this loss by oxidation, the surface of the melted metal is 
covered about i to | inch deep with powdered charcoal. 
The lead vapors, which are very injurious to the respiratory 
organs, are cari'ied offHlirough a chimney indicated in Figs. 
26 and 27. 

Besides unequal heating or over-heating, the disadvan- 
tages which may arise from heating steel in melted lead are 
as follows : Impure lead containing sulphur yields a por- 
tion of the latter to the steel, the previously described soft 
spots being formed. Hence, to be sure, the freshly melted 
lead is for a few hours boiled before being used. When: 



APPLIANCES FOR HARDENING STEEL. 59 

tools are heated in melted lead some of the latter readily 
adheres to some portions — in corners, on teeth, or other de- 
pressions — and prevents the hardening fluid from coming 
on these places in contact with the tool, and the latter 
here and there remains soft. To avoid this, cleanse the 
tools before hardening with benzine or alcohol from adher- 
ing grease, and brush them over with a mass of dough-like 
consistency prepared by mixing 1 part by volume of finely 
powdered charcoal (charred leather), 1 part by volume of 
rye flour and 1 part by volume of common salt with 
saturated solution of common salt in water. 

Dry slowly and carefully the articles brushed over with 
this mixture before immersing them in the melted lead 
bath. 

Although heating steel in fused salts may be designated 
as one of the best methods, it is not very widely practised, 
but where it is in use the great advantages offered by it are 
highly appreciated. 

No absolute rule as to the mixture of salts to be fused 
can be given, it depending chiefly on the purpose it is to 
serve. Pure readily-fusible salts which, when heated above 
their melting points, rapidly volatilize are, of course, un- 
suitable, as well as salts which, by reason of their chemical 
composition, exert an injurious effect upon the steel to be 
heated in them. 

On account of its special fitness and cheapness, common 
salt forms the chief constituent of the mixture. By the 
addition of a small quantity of readily-fusible soda (carbon- 
ate of soda), fusion of the common salt is accelerated, and 
the fluidity of the melted mass is increased by an addition 
of a small quantity of saltpetre. An addition of potassium 



60 TOOL-STKEL. 

chromate or of borax improves the properties of the bath, 
as well as an addition of yellow prussiate of potash, a pos- 
sible injurious effect of the saltpetre, by decarbonizing the 
steel, being thereby prevented. 

The salt is fused in a cast-iron crucible bricked in a fur- 
nace, such as shown in Figs. 25 and 26, the operation being 
as follows : Cover the bottom of the crucible, about one- 
third inch deep, with soda solidly rammed down, and fill 
the crucible up to the edge with common salt. Then heat 
the whole until fusion is complete. Now add gradually to 
the melt enough common salt sufficiently to fill the cruci- 
ble, and then add about 5 per cent, by volume of saltpetre 
and 10 to 15 per cent, of potassium chromate. 

Yellow prussiate of potash in small pieces is added to 
the melt as required, a larger quantity of it being used if 
the cementing effect is to be increased. In using yellow 
prussiate of potash it must be borne in mind that the 
vapors evolved are very poisonous and should be removed 
by means of a pipe. 

As regards the condition of the articles to be heated, it 
may be mentioned that they must be free from liquid im- 
purities ; adhering oil or fluid fats must be previously 
removed by means of benzine or alcohol. Water should 
be particularly avoided, as the introduction of moist articles 
might readily cause an explosive ejection of the melted 
mass. Very cold articles should be warmed before being 
immersed in the melt. 

The articles are suspended in the melt by small hooks, 
or they may be secured by ordinary iron wire. Articles 
which are to be partially hardened are held with tongs 
which should be perfectly dry. 



APPLIANCES FOR HARDENING STEEL. 61 

With this method it is of course also possible to overheat 
the melt, but this soon causes bubbling and running over, 
so that it can be more readily avoided than with the use of 
lead. However, unequal heating of the melt may readily 
occur. It may be detected by pushing a steel rod into the 
melt and observing the degrees of heating of various parts 
of it ; the working of the furnace is regulated accordingly. 

The disadvantages due to melted lead sticking to the tool 
are avoided with this method, the salt coating cracking off 
immediately from the tool when the latter is plunged in 
water. 

The tools heated in melted salt retain their pure metallic 
surface after hardening. Articles which before hardening 
are coated witli a layer of oxide, show after hardening a 
pure, smooth surface free from all scale. When to the salt 
melt larger quantities of yellow prussiate of potash are 
gradually added it exerts, in heating iron and steel, a strong 
cementing effect, so that wrought iron, otherwise not capa- 
ble of being hardened, acquires, when treated in it, a surface 
as hard as glass, and the hardness of steel is not immateri- 
ally increased. 



62 TOOL-STEEL. 

VIII. 

HARDENING OF TOOL-STEEL IN GENERAL. 

By hardening is understood the rapid cooling of steel 
from a distinctly perceptible red heat to a lower degree of 
temperature. 

Before discussing the means which may be employed for 
cooling the steel to be hardened, it is necessary to refer to 
the changes the steel undergoes in hardening. 

Steel when being heated for hardening must acquire a 
certain temperature if, after the subsec^uent rapid cooling, 
it shall possess hardness. The hardening temperature to 
be employed lies between 1202° and 14.S2° F., it being 
closer to the former for hard steel and closer to the latter 
for soft steel. 

Hardened steel when gradually reheated to a higher 
temperature constantly loses in hardness, and has lost it 
entirely on acquiring a dark brown-red heat which is per- 
ceptible only in a dark room. 

If the steel thus heated possesses a pure metallic surface, 
the latter, on heating, becomes coated with a film of iron 
oxide (ferroso-ferric oxide) which shows different colors at 
various degrees of heat. By this color — called temper-color 
— appearing upon the surface of the steel it may be judged 
what degree of temperature has been attained, and also 
whether heating has been uniform and sufficiently high for 
the desired degree of hardness. 

With steel of different degrees of hardness, the temper- 
colors do not appear at exactly the same temperature. 
Hence their selection depends on the character of the steel 



HARDENING OF TOOL-STEEL. 63 

used, but primarily on the degree of hardness previously 
given to the steel, and on the purpose for which the tool is 
to be used. 

It is generally customary to temper the finished tools 
before they are used in order to lessen the brittleness in a 
hardened state and to impart to them the degree of tough- 
ness required to save the parts engaged in use from 
breaking. 

For the reason previously mentioned, only general hints, 
which will be found in the table, facing p. 22, can be given 
for the selection of the temper colors. 

For the appearance of the temper colors it is absolutelj'' 
necessary for the pure metallic surface of the heated steel 
to come in contact with the air. Perceptible temper colors 
do not appear on impure surfaces, for instance, such as are 
•covered with fat or other substances, nor on steel which, 
for the purpose of being tempered, is immersed in melted 
metal of a fixed temperature. 

The changes which steel undergoes in hardening are 
chiefly due to the condition in which it was previous to 
this operation. By rapid cooling the hardening carbon 
which is formed by heating the steel becomes fixed and 
the structure of the steel concretes in the same condition 
in which it was at the time of hardening. This fixation 
-extends also to the volume of the steel. Steel, like nearly 
all other metals, expands by heating, its volume being 
increased in the direction of definite dimensions. In hard- 
ening steel, i. e., by rapid cooling in a lower temperature, 
heat is so rapidly withdrawn from it as to give the harden- 
ing carbon no time to be reconverted into carbide carbon, 
in which state the carbon occurs in unhardened steel. 



04 



TOOL-STEKI-. 



The structure of the steel attains a state of rigidity and 
in this condition opposes considerably more resistance to a 
change in form than before, and in overcoming this resist- 
ance the component parts of the structure are not displaced 
but completely sepai-ated (torn, broken). 

Hardened steel can no longer contract, and when once 
hardened also retains the larger volume which it possessed 
in the heated state. The fixed dimensions in the direction 
of thickness, and to a more limited extent, in that of 
breadth, are greater after hardening, while the length of 
hardened steel is less than previous to hardening. 

These changes in the dimensions of the steel can practic- 
ally be determined only with very accurate measuring in- 
struments, though under certain conditions they become so 
great as to be perceptible to the naked eye. This may 
be observed on tool steel which has been repeatedly hard- 
ened without being annealed before each hardening. 

When a piece of flat steel about 1| inches wide, 0.39 
inch thick and 3^ to 6 inches long, or a crude cutter about 
If inches in circumference and 0.47 to 0.59 inch thick, is 
hardened, then returned to the fire, and after carefully 

heating to the hardening 
temperature, again hardened, 
and these operations be re- 
peated ten to twenty times, 
the changes in volume which 
the steel suffers are very con- 
spicuous, and the changes will 
be the greater the harder the steel is. They are illustrated 
in cross-section in Fig. 28. For the experiment a steel 
plate with 1 per cent, carbon and 3.071 inches long, 1.732 



Fig. 28, 




HARDENING OF TOOL-STEEL. 65 

inches wide and 0.315 inch thick was used and hardened 
fifty-one times. 

Repeated hardening could by no means cause such con- 
siderable changes in form if the steel every time it was 
heated previous to hardening would reassume its original 
dimensions. Such is the case only when the steel after 
heating is allowed slowly to cool. Simply heating the steel 
before hardening is not equivalent to annealing, if heating 
is not succeeded by slow cooling. 

Strains which were in the steel before it is hardened are 
not removed by simply heating in hardening, but are even 
increased or enhanced after this operation. Special stress 
must be laid on this, because the incorrect view is very 
frequently held that heating before hardening is equivalent 
to annealing, and that such heating suffices for the compen- 
sation of the strains in the steel. As mentioned in a pre- 
vious chapter, in working steel its structure undergoes a 
change, it becoming the denser the more vigorously the 
steel had previously been worked and the lower the tem- 
perature at which the operation had been performed. The 
steel decreases in volume while its specific gravity becomes 
higher. The component parts of the structure are then 
under the same influence as in hardened steel, i. e., in a state 
of rigidity which is much increased by hardening if the 
steel is not previously annealed. Hence there is greater 
danger of cracks being formed in consequence of the 
greater brittleness of steel not annealed. 

The above described property of steel of assuming fixed 
dimensions in hardening operations immediately succeeding 
one another is practically utilized, for instance, with draw- 
plates. When the hole by iise has been enlarged, the 
5 



QG TOOL-STKKL. 

draw-plate is hardened without previous annealing, the 
result after each repetition of the process being a contrac- 
tion of the hole. If tool-steel of the same degree of hard- 
ness of, for instance, a round or square cross-section, be 
notched at distances of about |, 1 and 1| inches from each 
other, and then hardened and broken on the notched places, 
the fractures allow of the following observations being 
made : 

The steel with the smallest cross-section will throughout 
show a uniform, fine structure over the entire fracture if 
the steel used for the experiment contained more than 
about f per cent, carbon, and heating before hardening 
had been uniform throughout. The heat from the interior 
of the steel has been yielded up to the hardening fluid with 
sufficient rapidity to produce uniform hardening through- 
out the entire cross-section. 

On the fracture of the steel with medium cross-section 
will be noticed a symmetrically arranged core of coarser 
structure, which shows quite sharply defined boundaries. 
The hardness of this core will be somewhat less than that 
of the surface. The delivery of heat from the interior 
could not progress rapidly enough, and the hardness is not 
so great as on the surface ; hence the structure remains 
coarser. 

This phenomenon is still more strikingly perceptible on 
the fracture of the steel with a larger cross-section. The 
interior of the steel shows, increasing towards the centre, a 
coarser structure and considerably less hardness than on 
the outer edges. 

The above described phenomenon is seldom sufficiently 
taken into consideration. However, when considered in 




HARDENING OF TOOL-STEEL. 67 

connection with the fact that hardened steel increases in 

volume, it is of the greatest importance for the practice of 

hardening, especially as regards the mode of cooling the 

steel to be hardened. 

In Fig. 29 the dotted line represents the cross-section of 

steel not hardened, and the full line the ^^ „„ 

' Fig. 29. 

cross-section of the same steel hardened. 
By two concentric circles the surface is 
divided into three parts, of which a repre- 
sents the surface of greatest hardness, 6 that 
of less, and c that of least, hardness. 

Assume the zones thus formed to be continued through- 
out the entire piece of steel, spaces are formed inside 
of which the steel is of approximately the same char- 
acter. For instance, in the space a the steel acquired the 
greatest hardness and in consequence also the greatest per- 
manent expansion; in the space b the hardness as well as 
the permanent expansion is less, the steel in consequence 
of slower cooling having a tendency to contract somewhat 
in this zone. In the space c the delivery of heat proceeded 
still more slowly, and the steel has the least hardness and 
the greatest tendency to occupy the original volume it 
possessed before hardening, i. e., to contract. 

Now, if instead of two zones, we assume the interior of 
the steel to be divided into innumerable such zones, it may 
be imagined that each zone in its endeavor to contract, 
exerts, commencing from the surface towards the centre, a 
strain of constantly increasing force upon the outer portions 
of the steel. 

When the force of the strain developed in the separate 
parts has become so great as to overcome the strength of 



(>S TOOI.-STKKI,. 

Ilu' s(<««'l. ii (lis|il!H'oiiUMit ol' llu' particles of its st luclurc 
takes plaro, tlu" st(>i'l sulVcriiiLi an ('Xpansion, wlicrrhy llic 
(owe o\' tlu' strain is i'lu>i'kiMl or tlimiiiislicil. 'I'lic ^ri-ati'r 
tlu' (li\L:,ro(> ot' lianlnoss wliicli tlu> stt'ci possesses, the loss it 
will ho oapahlo of oxpaiulinu,', and tlic sdohcm- a st^paniiiou 
of the paitii'K's of llit> sti'iu-lurc aiul consotnuMitly crackitii; 
will take i>laco. 

This rra«.'kin«i ot'tlu> stiH^l, however, does nt)t always oriii- 
inato in the juM'tituis where tlu> most powerful strain pre- 
vails, hut in the j>oi'tions of tlu> steel whieh possess tin- lc\ast 
(leii'ret* of (>xtensihility and lon^lnu^ss. This is «i'eiu<rally 
the easi> on tlu> eorniM-s and etl^H's. tlu\\ hein^ hardest, and 
seldom in th(> hody ol' the tool, the softer eore oi' whieh will 
expand without eraekinii. 

The strains in the nitenor o[' the stt>el may. however, he 
so iiri>a I that the limit ot" (*\tiaision ot' whieh the less hanl 
eore is eapahle is exeeeiled.* 'V\\o t'ormatitui o\' the eraek 
then i'onuneni-es in the interior o( tlu> sti>el. 

\\ hile era<'ks eomnuMU'inii' on or m>ar the surface are, as 
a rul(\ I'ormed i>arly ni the hardiaiiuii fluid, and -aw per- 
t'eptihle imnuNliately atter harthMiinL:,, si^veranee in the 
interior ^Mierally takes plaei> a i'i>nsiderahle tinu> affiT 
hardiMhuLi and t'requently causes the hardened tool to hi'cak 
only after several days. 

Crackino- which had its orii^in in the interior may frt^ 
tjucntly he ohserved on tools with a synni\etrical cross- 

^ \\'lu'n ti(0 intorUu' ot" tl\i' stool lias tlnws thio to Mistoi"s or pipos, or \v1um> 
in ooKsotiuoiu'o ol" litiuiiiation, tho stoil is o( varving olionuoal iMiupositioii. 
tlio ("onnatiiMi ol" onioks is tho moro smo to ooinmoiuv fivm tl\o iutorior. Tlio 
oauso o( tills —a dot'iH't in tlio stool- is, liowovor. plainly poivoptiMo on llio 
l"raotmo. 



(1 Ai!i)i':NiN(i OK '!'(>( n,-s'n';i':L. 



()9 



S(^cli(>ii ;iii(l oil l;ii|;(' d iiiiciisions, iis well iis vvlicii luird stcrl 
lias Ix'cii used, hcciiusc with a symiiicl lical cross-sec;! ion (ho 
C(!iilrcol' the siocl is siiniihaiicoiisly subJ(!c((Ml IVoiii several 
sides to a poweri'ul strain, and in hard steel llie strains ar(5 
purtieularly ^reat, its toughness heiiij^ hut slight- 
Thin flat steel, |>rolile steel of slight, t liickiKiHH, etc., are 
I(iss lial)le to cracking in (he iiiteiioi' tJiaii round or s(|uare 
ste(;l, oi' cubes and halls. 

In observing the Craclureof liai'deiie(| steiil of a larg(!r 
cross-se(;tion, it, will he iioticc(| that- a narrower' or wider 
border of an entii'cly uniform structure and <'(|ual hardness 
passes abruptly into an endless curved core of less liardness 
and of coarser structure. On the boundary between both 




of them, close to the surface, are located tiie greatest strains, 
the steel possessing here tlie least toughness, and it cracks 
along the course of this boundary, iKiUce g(;n(!i'ally in a, 
curve. The corner's of a, culx;, if the latter he repeatedly 
heated, will be; sev((i'c<l, as shown in I'^ig. .'JO, in the lirst 
hardening if the steel is hiit.t.h^ oi- has become so by over- 
heating. The severance of the teeth of cuttei's also takes 
place in a line nnming in a cuive along the boundary 
above descrilxid, and that of the face of a hammer as 
sketched in Fig. 31. 



70 



TOOL-STEEL 



The force of the strain in forming cracks may Irequently 
be so excessive, especially with hard steel, that when the 
latter cracks the fragments are hurled about with groat 
force. 

Fig. 31 . 




Fig. 32 represents a round bar of particularly hard 
special steel which, after hardening, has cracked from the 
interior. The force of strain exerted upon tlie interior of 
the steel may be judged from the manner in which the two 
halves are bent. 



Fig. 32. 



Fig. 33. 



S^^^ 





Fig. 33 shows a roll-cutter, the corners of which have 
been severed during the hardening in the direction of the 
above-mentioned curved line. 

The above-mentioned forces are at work at every 
hardened tool and frequently cause cracking, even with 
the use of sound steel, if hardening has been done in a 
faulty manner, and it has been neglected to lessen the 
brittleness of the hardened steel by annealing at the proper 
time. 

The previously described strains which in hardening are 
formed in the direction of the cross-section bv an increase 



HARDENING OF TOOL-STEEL. 71 

in the dimensions in the directions of the width and the 
thickness are highly influenced by the strains which are 
formed in consequence of the steel contracting in hardening. 
The eff'ect of these strains may be readily followed up by 
bearing in mind that the outermost layer of the steel which 
has been uniformly hardened has experienced a contraction, 
while the more slowly cooling core has a tendency to ex- 
pand. In consequence of this, strains are formed in the 
layer of greatest hardness parallel to the direction of its 
length. These strains in the direction of the length cause 
a distortion of the steel if the latter has not been uniformly 
cooled in hardening. When a flat bar of steel is uniformly 
heated and the edge is lengthwise plunged in water so that 
about one-half of its width is cooled, it contracts on this 
side, while the uncooled portion projecting from the w^ater 
expands. In consequence of these forces acting in a dis- 
similar manner, the steel acquires the form of a sickle, the 

Fig. 34. 
Before Aff«r 

Coo//'njjr 





hardened portion curving inwardly and the unhardened 
portion outwardly. 

If the bar of steel be bent together to a ring not entirely 
closed, and is then heated red hot, and the outer side of the 
ring is rapidly cooled, it will contract and cause the ring to 
open, see Fig. 34. 



72 TOOI--STKEL. 

In hardeniiio- t()<)ls of an annular cross-section, the cir- 
cumference becomes smaller, while the interior layers which 
have been less cooled endeavor to expand. The outiM- hard 
layer of the steel lies like a ring upon the interior layers, 
and the latter in their endeavor to expand make an effort 
to break the ring and frequently succeed in doing so. The 
cracks formed commence on the surface, and when once 
formed continue in the direction of the centre throughout 
the entire cross-section. 

From this phenomenon we learn that by each heating, 
which in the interior of the steel acts upon layers already 
cooled, the endeavor to expand is increased, and the danger 
of cracking on the surface enhanced ; and the latter may 
even be first caused by it. 

Cracking may be prevented by heating the steel from 
the outside, whereby the exterior hard layer is made 
tougher and the change in form can more readily take 
place. 

The explanations given above of course refer only to tool- 
steel of normal composition, which can be well hardened. 
Steel less capable of being hardened when heated also suffers 
a change in volume, which, however, is not fixed by hard- 
ening, the hardness not penetrating to a sufficient depth, so 
that the hardened layer follows the re-expanding inner 
layers. 

Manganese exerts a great infiuence upon the change in 
volume of the steel in hardening, and under certain condi- 
tions prevents it entirely. Ingot steel, still capable of being 
well hardened, with about 0.45 carbon and a higher con- 
tent of manganese (0.8 to 1.0 per cent.) scarcely undergoes 
a change in its dimensions in hardening. 



HARDENING OF TOOLS. 73 

Hence such steel is used for tools on which no great de- 
mands are made and the dimensions of which must not be 
changed by hardening. 



IX. 

HARDENING OF TOOLS WHICH ARE TO BE 
HARDENED IN THEIR ENTIRETY. 

From what has been said in the previous chapter, it is 
evident that the changes in volume caused by hardening 
and fixed by it are the immediate cause of cracking. By 
letting down the steel, /. e., by toughening it or making it 
more viscid, the particles of its structure can partially follow 
the changes in form and cracking is avoided. This tough- 
ening, however, must be done at the proper time, in fact, 
already during hardening, and hence belongs to the latter 
operation. 

Below will be described the means by which failure in 
hardening may be avoided by letting down. 

Before proceeding with the operation of hardening, the 
hardener should first of all form a clear idea of the portions 
■of the tool in which formation of cracks is to be feared, and 
take such measures as may serve for the avoidance of them. 

As a general rule it may be assumed that all projecting 
parts of a tool — corners, edges, teeth, etc. — will be most 
subject to snapping off or superficial separation. 

Cracking from the interior is to be feared with massive 
iools of large dimensions. If such tools possess, in addition, 
projecting parts on the surface, as for instance, large screw 



74 TOOL-STEEL. 

taps, broaches, cutters, etc., the severance of these parts is 
the more to be feared the Larger are the dimensions of the 
massive portions of the tools. 

By letting down the steel on the surface where it pos- 
sesses the greatest hardness, the particles of the structure 
acquire greater mobility ; the condition of greatest rigidity 
being destroyed. In consequence of the greater toughness 
or viscidity thereby obtained, a scale-like separation of por- 
tions on the surface of the tool is avoided if letting down 
be effected at a time when se[)aration has not already taken 
place. 

As previously mentioned, cracking on or near the surface 
generally takes place already during cooling and is brought 
about the more readily the harder the steel is, the higher 
the temperature at which it has been hardened, and the 
colder the hardening fluid has been. If, for instance, a 
massive cutter with many teeth be hardened in water and 
allowed to cool only so far that when under water it can be 
touched with the hand, a crack will seldom be observed on 
the teeth. If, however, it be immediately returned to the 
cooling: bath and allowed further to cool, the severance of 
single, and sometimes of all the teeth takes place very rap- 
idly, and continues after the entirely cooled cutter has been 
taken from the hardening bath. When cracks on the sur- 
face are formed, a peculiar chinking noise well-known to- 
experienced hardeners is heard. The snapping off of the 
teeth of the cutter is due to the fact that cooling off has 
been continued until the outermost, hardest layer has ac- 
quired the highest degree of brittleness and hardness, and 
the supply of heat from the interior was no longer sufficient 
to maintain it in a state of greatest toughness or viscidity. 



HARDENING OF TOOLS. 75- 

The power of resisting the strain, which increases in force 
with progressive cooling, becomes less and is finally over- 
come. 

Superficial scale-like separations on tools are avoided by 
interrupting cooling ofi' at a period when the tool is com- 
pletely hardened but not entirely cold (fractional hard- 
ening). 

When the tool which is now allowed slowly to cool, still 
retains sufficient heat in the interior to heat the surface to 
a high degree, it may completely lose the hardness pro- 
duced ; it becomes soft. 

To prevent this, the partially cooled tool is not allowed 
to get cold in the air, but is brought into a fluid which 
withdraws the heat less rapidly than the hardening fluid — 
generally oil or melted tallow — in which it is allowed 
quietly to cool. However, this process cannot always he 
relied upon, and in practice is reluctantly resorted to if 
the highest degrees of hardness are positively to be ob- 
tained. 

The highest degree of hardness, however, is only attain- 
able when the tool is so completely cooled in hardening 
that actual letting down from the interior is out of the 
question. 

By reference to the table facing p. 22 it will be seen 
that the pale yellow temper-color commences to appear on 
the heated steel at a temperature of 428° F. The tool 
completely cooled off and hardened on the surface can 
therefore without hesitation he heated from the outside to- 
about the above-mentioned temperature without fear of an 
appreciable loss in hardness. 

B}' this heating from the outside, the rigid hard surface- 



70 



tool-steh:l 



of tlie tool acquires a somewhat greater toughness or viscid- 
ity and can more readily follow the changes in volume of 
the interior without separating or losing in liardness. 

This process is very frequently applied in practice by 
the hardener immediately returning the tool, when nearly 
completely cooled, to the hardening fire and at the same 
time heating it to a low degree of temperature at which an 
actual oxidation cannot take place. The reheated tool is 
then allowed slowly to cool. Great skill is, however, re- 
quired for heating the steel very uniformly in the harden- 
ing fire, and preventing the sharp edges and corners from 
being finally overheated. Hence it is preferred to reheat 
the tool in hoi sand or hot water instead of in the harden- 
ing or forge fire. 

For this purpose the sand in a vessel is heated to such a 
degree that it can no longer be touched with the hand and 
small quantities of water poured upon it evaporate without 
hissing. The hardened tool is then at the proper time 
brought into the hot sand, and after being uniformly 
covered with it, allowed to cool. The manipulation with 
hot water is safer as regards the temperature to be used in 
reheating. The tool when almost completely cooled is 
quickly plunged in boiling or highly heated water and 
allowed to cool in it. 

If the tool has been brought too soon into the hot water, 
i. €., at a time when enough heat is still stored in the in- 
terior which in conjunction with the heat acting from the 
exterior would suffice to cause a decrease of hardness, the 
tool is after a few minutes returned to the hardening bath, 
again cooled off, and finally allowed to cool entirely in hot 
water. 



HARDENING OF TOOLS. 77 

The above-described process for protecting, during hard- 
ening, tools which are to be hardened in their entirety from 
possible cracking from the outside or inside by partial 
letting down or toughening, can be recommended for all 
kinds of tools without regard to their shape or size. 

In some cases it is recommended to allow the hardened 
tool to remain in the hardening bath until it is entirely 
cold, and for a considerable time afterwards. The object of 
this process is to maintain undiminished the highest attain- 
able degree of hardness in the interior of the tools. Letting 
down for the purpose of obtaining greater toughness or 
viscidity on the surface is then effected by the application 
of heat from the outside to the tool when completely cooled. 

To be sure in iising this process there is a risk of the loss 
of the tool. Scale-like separation of the corners and edges 
frequently takes place, particularly with the use of especi- 
ally tough steel, though cracking of the piece from the 
interior occurs less frequently. The process finds practical 
application in hardening tools which work under especially 
high pressure. Large tools, for instance, rolls, or tools of 
especially complicated form, for instance, hollow bodies, 
tubes, etc., cannot be hardened by the process customary 
for smaller tools without fear of failure. For cooling such 
tools special devices are required, a detailed description of 
which will be given later on. 

The hardening of tools the entire surface of which is to 
be uniformly hard, makes the greatest demands on the skill 
and experience of the hardener and requires the best kinds 
of appliances. 

However in practice it does not alone suffice to pro- 
tect one's self from the loss of a tool in hardening by heat- 



78 



TOOI.-STKE1-. 



ing and cooling in ;ni aj)[)ropriato manner in order to dc- 
-crease the danger of cracking, but it is also necessary for 
the designer of the tool to take into consideration the influ- 
ence of the forces wliich are formed in hardening and 
directed towards the destruction of the tooL 

In some cases almost impossibilities are demanded from 
the hardener, the strangest shapes being, for instance, given 
to cutters without considering that the danger of the loss 
of the tool in hardening increases with size and complicated 

Fk;. 35. 

//»p/i>ee of ^a// ,_^^ D/'y/ifef 




form, even if hardening has been done with the utmost 
care. Hence, tools of large or complicated shapes are, as 
far as their mode of ap})lication permits, divided into sev- 
eral sections, which when })ut together form the finished 
■tool. Thus, for instance, long plane cutters are made in 

Fio. 36. 





-several short pieces, as shown in Fig. 35. The cutting 
surface is laid obliquely to the axis of the tool so that the 
joint is not detrimental to the cleanness of the work. 

With thick irregular shapes, as shown in Fig. 36, the 



HAKDExMNG OF TOOLS. 



79 



danger of cracking IVom the interior in consequence of 
unequal rapid cooling is diminished by boring out so as to 
give the walls of the tool as nearly as possible the same 
thickness. In other cases the strains in the interior of a 
tool with symmetrical cross-section are diminished by bor- 
ing it out. Ver}' large taps, broaches, etc., which after 
hardening readily crack from the interior and cool with 
difficulty in consequence of the heat stored in the interior, 

Fig. 37. 



Bored-ot/f Broach of Large eross-secf-ion . 




-l|. _ Ui _ 



are bored through in the direction of their length, as shown 
in Fig. 37. 

In solid tools the strains formed in hardening converge 
in the centre, while in tools bored out they are distributed 
upon the circumference of the bore. 

An enumeration of all the cases in which the danger of 
failure in hardening may be diminished by a very simple 
change in the form of the tool is, of course, out of the ques- 
tion, but it may be mentioned that in practice such cases 
are quite numerous. 

The main points to be considered in the construction of 
a tool are whether its form is as simple as possible and 
whether the projecting portions correspond favorably to the 
bulk of the tool ; further, whether sharp corners and edges 
are as much as possible avoided, and whether there is a 
gradual transition of different cross-sections. 



80 TOOL-STKEL. 

X. 

HAKDKNIN(; OF TOOLS WHICH ARE ONJ.Y TO 
BE PARTIALLY HARDENED. 

The operation of hardening tools which must i)Ossess 
throughout a uniformly hard surface, as described in the 
previous chapter, presents the greatest difficulties to the 
manufacturer of tools, and requires considerable skill and 
experience. 

However, the greater number of tools are only partially 
hardened, namely, the parts which in use are subject to 
great wear, while the other portions are to be as tough as 
possible. 

With reference to the main points and the nature of the 
tools, partial hardening may be divided into three groups 
as follows : 

1. In heating the tool for hardening, every portion of it 

which is to be hardened may be heated to such an 
extent as is required to obtain a uniform degree of 
hardness, and the operation of hardening may also 
be carried on accordingly, for instance, with turning 
knives, chisels, gouges, etc. 

2. On account of its small size or shape, the entire bulk 

of the tool to be partially hardened has to be heated, 
but hardening may be partially effected as, for in- 
stance, with hammers, sledges, small punches, short 
and broad-cutting knives, etc. 

3. The tool must be heated and hardened all over to 

pi event distortion, partial cracking, etc. The hard- 
ness of the portions of the tool not subject to wear is 



HARDENING OF TOOLS. 81 

after hardening reduced by reheating, for instance, 
with all kinds of knives (shear-knives, wood-planing 
knives, stamping knives for paper and leather). 

What has been said in reference to heating tools which 
are to be hardened all over, ap])lies also to partial hard- 
ening, i. e., the steel must under no conditions be heated 
too highly, or unequally on the places to be hardened. 

Heating must also be so etiected that the portions to be 
hardened show a uniform hardening temperature which in 
not too rapid gradation decreases in the portions of the tool 
not to be hardened. 

When a tool runs to a thin edge the latter becomes warm 
in the tire and is readily overheated before the portion 
further back acquires the required temperature. In this 
case the portion back of the edge is first heated to a dark 
cherry red, and then the edge to the hardening temper- 
ature. 

If the portion of the tool to be hardened possesses a small 
cross-section running rapidly and 
quite immediately into a larger '^' 

cross-section, for instance, a 
punch. Fig 38, the thicker por_ 
tion a is first heated until it 

shows the proper hardening temperature, and then the 
thinner portion b. 

Broad cutters may in heating be readily overheated on 
the sharp corners if not protected therefrom by occasional 
cooling off. Such cooling off, in case the corners should 
show a higher temperature than the other portions of the 
cutter, is effected by dabbing them with a moist rag or 
scattering upon them a dry powder consisting of: 
6 




82 TOOL-STKEL. 

Calcined common salt 1 [Kirt by volume. 

Pulverized hoofs 1 part by volume. 

Powdered charred leather 1 j)art by volume. 

Rye flour 1 part by volume. 

If, on account of their form, tools which are to be par- 
tially hardened have to be heated all over, it must be done 
so that the portion to be hardened acquires last of all the 
proper hardening temperature, the portion not to be hard- 
ened being, therefore, first exposed to the higher tempera- 
ture in the fire. As regards tools vvhich are to be partially 
hardened, it may be mentioned, that by cooling them a 
sharp line of demarkation between the hardened and un- 
hardened portions should never be allowed to form, but 
there should be a very gradual transition of one into the 
other. 

If a bar of steel be heated to a uniform cherry-red, and 
then immersed to a certain depth in water and cooled so 
that a sharp line of demarkation is formed between the 
hardened and unhardened portions, and an experiment be 
made in breaking the bar, fracture will take place the more 
assuredly on the line of the hardened part, the harder the 
steel used. 

The strains on the sharp boundary of the hardened por- 
tions are sufficiently great to make such demands on the 
strength that less force is required to produce fracture along 
this line than on au}^ other places of the steel. In use, tools 
thus hardened, soon break along the boundary between the 
hardened and unhardened portions, if it does not already 
occur in hardening. 

A gradual progress of hardening is attained by slowly 
moving the tool up and down during cooling. 



(;0()L1N«> OF TOOLS IN HARDENING. 83 

If tools are to be hardened so that there is a gradual 
transition of the hardened into the unhardened portions 
with rapid cooling, as is frequently desirable in the manu- 
facture on a large scale, the appliances for heating must 
of course be made with great care, so that abrupt transitions 
of temperature do not occur on any portion ot the tool, be- 
cause when such is the case, partial hardening also causes a 
sharp line of demarkation between the hardened and un- 
hardened portions. 



XL 

COOLING OF TOOLS IN HARDENING AND 
DEVICES FOR THIS PURPOSE. 

The general rule for cooling tools is of exactly the same 
purport as that for heating them for hardening, namely, 

Cooling of the red-hot tool should be effected so evenly 
that the heat is uniformly withdrawn from the por- 
tion to be hardened. 

This rule seems very simple, but in practice it is not 
always easy to follow it, because even by simply immersing 
the red-hot tool in the hardening fluid, unequal cooling 
takes place at the outset. 

While the tool remains in the hardening bath, steam is 
formed by the evaporation of the fluid, and where the steam 
cannot escape with sufficient rapidity the tool is enveloped 
by a layer of it which prevents uniform hardening. Hence, 
the article to be cooled must be kept in constant motion so 
that it always comes in contact with fresh layers of the 



84 TOOL-STKKL. 

hardening Huid, and tlie steam evolved can escape with 
greater facility. However, by this motion the separate 
sides of the tool are alternately brought into more energetic 
contact with the cooling fluid and also unequally cooled, 
the consequence being that the tool warps or cracks. 
When the tools to be hardened are small, heat is very 
rapidly withdrawn from them and unequal cooling by im- 
mersing and moving them about seldom causes warping or 
cracking. 

When especiall}' large and lieavy tools are to be hard- 
ened, or tools which on account of their cross-section show 
a ready tendency to warp, they are not moved about in the 
hardening fluid, but the latter is set in motion. This 
motion may be a simple one, when the hardening fluid acts 
from one side upon the tool, or a combined one, when it 
acts simultaneously from several sides. 

Before entering upon a further explanation of what has 
to be observed in the actual hardening of tools, attention 
may be drawn to a very important fact which may often 
be noticed. 

It frequently happens that tools which have been heated 
with the greatest care are previously to hardening, exposed 
to cooling, and then hardened when in a state of unequal 
temperature. As a rule this is not taken into consideration 
and ultimate failure in hardening is ascribed to entirely 
different causes. 

Unequal cooling of the tool immediately before harden- 
ing may be caused by a sharp draught of air, and this 
should be avoided as much as possible in the neighborhood 
of the hardening fire. When the red-hot tool for the pur- 
pose of hardening is brought from the furnace or fire, it is 



COOLING OF TOOLS IN HARDENING. 85 

frequently laid upon cold iron plates or even upon a damp 
support to facilitate catching it with the tongs. The un- 
equal cooling thus induced is frequently the cause of cracks 
being formed. 

Catching the red-hot tool with cold tongs, or with tongs 
wet from a previous hardening operation, will almost 
always cause the formation of cracks, especially with a tool 
of a small cross-section, since uneven cooling penetrates 
immediately, the entire cross-section. Such a tool is best 
heated by catching it with the tongs and heating it to- 
gether with the latter. When this cannot be done, the 
jaws of the tongs should be heated to a dark red heat each 
time before seizing the red-hot tool. Cracks which are 

Fig. 39. 
a a, CracK 



formed by uneven cooling from catching with the tongs, 
as a rule, run a quite regular course, they being formed 
either in the direction of the length of the tool, or return 
in a curved line to the initial point. The dotted line in 
Fig. 39 shows the course of such a crack on a twist-drill. 

When a tool which is to be hardened is grasped with the 
tongs and together with the latter immersed in the harden- 
ing fluid, care should be taken that the jaws of the tongs 
come in contact with as few points of the tool as possible, 
because the portions of the latter covered by the tongs do 
not cool with sufficient rapidity ; the consequence being 
uneven hardness, and cracks commence to form on the 
places grasped by the tongs. For catching tools to be 



86 



TOOI--STKKL 



hardened, tongs with jaws terminating in as sharp points 
or edges as possible should be used. Tools bored through 
are taken up with a hook pushed through the bore. 

Fig. 40 shows a cylindrical revolving knife held by 
tongs properly selected ; Fig. 41, a cutter, and Fig. 42, a 
cutter grasped with an iron hook. On the other hand, 
Fig. 43 shows a cutter held by tongs not suitable for hard- 
ening purposes. 

In many cases when thin flat tools are to be j)artially 
hardened, the portions not to be hardened are covered 
before cooling with pieces of sheet-iron, etc., or the tools are 
grasped with tongs, the jaws of which are so shaped as to 



Fig. 40. 



Fig. 41. 



Fig. 42. 



Fk;. 43. 




form the covering. However, cracking and distortion of the 
tool are frequently caused by this mode of partially hard- 
ening, and it should only be used with very soft varieties of 
steel which require merely superficial hardness. When thin 
flat articles, some portions of which have l:>een covered, 
are heated and hardened, a sharply defined boundary, in 
accordance with the extent of the covering, is formed be- 
tween the covered portions, which are not at all or only 
slightly hardened and the portions which are completely 
hardened. The thicker the covering is, the more sharply 



COOLING OF TOOLS IN HARDENING. 



87 



defined this boundary will be. In order to broaden the 
transition from the unhardened to the hardened portions, 
the covering should be thinner towards its edge, and the 
latter should not very firmly rest upon the article. How- 
ever, when the same object can be attained by another 
method, for instance by reheating the hardened portions 
which are to be soft, it is to be preferred. 

For thick tools of symmetrical form, unequal hardening 
by covering separate portions is employed when the strains 
formed in hardening are to be dispersed and not allowed to 
converge towards a centre ; further, when the zone of 
greatest hardness is to be limited to as small a space as 
possible. 

Fig. 44 represents one-half of a cutter which has been 

Fig. 44. 




hardened without covering. The exterior zone which has 
acquired the full degree of hardness is not hatched, and is 
bounded by the line a «/. Along this line the steel possesses 
least strength and, in hardening, separation of teeth will 
take place in accordance with it. From the point b and 
the line c, the strains act radially towards the exterior. 
When in hardening the same cutter is protected on the face 
by covering with sheet-iron discs as shown in Fig. 45, cool- 
ing and hardening proceed as shown in the sketch of the 
cross-section. The line a a' shows the course of the bound- 



88 



T()()I,-STKKI, 



ary of least streii^tli. The strains disperse themselves in 
parallel direction and separation of teeth in the direction of 
their course docs not so readily take |)lace.* 



Fi(i. 45. 




It is an absolutely necessary j)rovision for this mode of 
protection that the covering should project over the por- 
tions to be protected. If the covering were of a smaller 
extent, for instance as shown in P"ig. 40, the result would 



Fig. 4(5. 




be just the reverse from that intended, because a sharply 
defined boundary would be formed between the hardened 
and unbardened portions of the tool. 

The application of tJie ahove-wientioned method is of course 
very limited, and depends on the form of the tool as well 
as on the extemt of the svrface to lie hardened. 
It is largely employed in hardening rolls of very hard 

* Beside the above-mentioned strains in the direction of the cross-section, 
the entire circnmference stands under considerable strain, which is caused by 
its having been shortened by liardcning, and iiy the pressure of tlie inner less 
hardened layers upon the outer hard layer. 



COOLING OF TOOLS IN HARDENING. 89 

steel in order to decrease the dnnger of cracking, and in 
hardening parts of machines certain portions of the surfaces 
of which are to be hard to prevent rapid wear. 

Tools which by reason of their forms or dimensions have 
for the purpose of hardening to be heated in their entirety, 
should always be cooled in a fluid which is in a state of 
motion in such a manner that the surface to be hardened 
is exposed to a continuous stream. 

The most simple manner of effecting this is to immerse 
the red-hot tool in running water. However, uniform ac- 
tion by this means is only effected laterally and hardening 
in running water requires, as a rule, the immersion of the 
entire red-hot tool, consequently also cooling — hardening — 
of the portions not intended to be hard. Hardening in 
water running in a horizontal direction, for instance, in 
gutters, channels, etc., offers no appreciable advantages as 
regards uniformity of cooling, especially of larger surfaces, 
the onl}^ advantage being the relatively uniform temper- 
ature of the water on account of the latter being constantly 
renewed. The temperature of free running water is of 
course not absolutely uniform, it depending on the season 
of the year. 

The mode of using running water for hardening is as 
follows : The water is conducted into the vessel to be used 
for hardening purposes, and the supply regulated so that 
"the temperature remains the same even when hardening is 
continuously carried on. Fig. 47 shows a simple device 
for the purpose. The water runs in at Z and runs off 
through a notch A in the side of a barrel which serves as 
the hardening vessel. 

For hardening tools, special advantages are offered by 



90 T()f)l.-STEEL. 

the employment of lulling water, because it is feasible 
thereby to expose to it only the i)ortions of the red-hot tool 
which are to be hardened. The process of hardening by 
means of free-falling water is very simple, it being only 
necessary to expose the area to be hardened to the action of 
the jet of water until completely cooled. The main point 

Fig. 47. . 




■'V.y .'.••-.' 



in this process is that every i)ortion of the area to he hard- 
ened is uniformly struck by the jet of water. If the latter 
is not sufficient to cover uniformly the area to be hardened, 
it may be adjusted by moving the tool about, but the dan- 
ger of defective hardening is not entirely averted. 

With a plenitiful supply of water the device shown in 
Fig. 48 is very suitable for hardening under falling water. 
The water is conducted to the vat H, which may be con- 
structed of wood, iron, or brick, through the conduit L, the 
notch E serving for the overflow of the excess of hardening 
water as well as for keeping the latter at the same level. 
To the conduit L is fitted a cock the discharge opening of 
which is provided with a thread to which may be screwed 
a rose (see sketch Fig. 48). This rose comes into use when 
the water flowing from the cock M is to be distributed over 
a larger area. Of course with the use of the rose the water 
must flow under a certain pressure. The tool to be hard- 



COOLING OF TOOLS IN HARDENING. 



91 



ened is laid upon the grate Jt fixed under the cock M, and 
the latter being opened, cooling is continued until the tool 
is cold. In many cases, especially when very hard steel is 
hardened under the jet of water, the strains formed by 
hardening have to be somewhat equalized. For this pur- 
pose the tool is not allowed to become entirely cold under 
the jet of water, but hardening is interrupted at a suitable 

Fig. 48. 



A Snfe abohi nr^ttr lere/ 
R •»» btlow *»» ** 



Hammer-Head Ly/n^ o pon thegntt 




moment and the tool, hardened side down, is laid upon a 
grate extending somewhat below the surface of the water, 
upon which it is allowed completely to cool. Oxidation of 
the hard surface is prevented by fresh water running con- 
stantly in at the side (see sketch, Fig. 48). The cock M 
should extend to the centre of the hardening vat and should 
be movable so that it can be turned out of the way when 
not in use. 



92 



TOOL-STKia.. 



In case a water conduit or ruiinin<>; water is not avail- 
■able, tlie device shown in Fig. 49 may serve the {purpose. 

If is, of course, only intended for occasional hardening 
under the water-jet, or when for want of water flowing 
under pressure, hardening is to be effected in an ascending 
water-jet. 

The very simple device consists of two vessels H H, 
arranged one above the other. From the upper vessel H, 
a pipe /.' conducts the water to the cock M. The pipe R 

Fid. 4«>. 




Fig. 50. 




shown in the same sketch extends to the bottom of the 
vessel H and is then bent upward, thus causing the jet of 
water to ascend. When hardening is to be effected under 
an ascending water-jet and there is at hand neither a water 
conduit nor other device for producing a water-jet, a funnel 
constantly kept full by pouring in it a uniform supply of 
water may be used. Still more convenient is the use of a 
siphon made by bending a piece of gas pipe. For use the 
siphon is filled with water and brought into the position 



COOLING OF TOOLS IN HARDENING. 9S 

shown in Fig. 50. As the water flows from the siphon 
with but slight force, this device, of course, is available only 
for small areas. 

The object of hardening in an ascending water-jet is the 
same as in a falling water-jet, and its use is preferred if per- 
mitted by the form of the tool or the area to be hardened. 

A falling and an ascending water-jet are simultaneously 
employed in hardening tools which are to possess the same 
degree of hardness on two opposite sides, and one end of 
which, by reason of their short length, cannot be heated 
without the heat being at the same time transmitted to the 
other end, for instance, pivots, short hammers, sledges, etc. 

While tool-areas may under all conditions be hardened 
by means of a falling water-jet — and in some cases must 
even be thus hardened — the employment of an ascending 
water-jet depends on the form of the area to be hardened. 

When the area to be hardened is level or has elevations 
or bulges out otherwise, hardening may be effected with an 
ascending, as w^ell as a falling, water-jet, but the former 
method is to be preferred, since greater uniformity of hard- 
ness can be attained with it. If, however, the area to be 
hardened has depressions, or curves inwardly, hardening 
with a falling water-jet is the only method available. The 
vapors formed in cooling with an ascending water-jet can- 
not immediately escape, and being constantl}' reformed, 
prevent contact of the water with the steel so that harden- 
ing is not effected and the depressions to be hardened re- 
main soft. The device for hardening in an ascending 
water-jet is shown in Fig. 51. The supply pipe, it, is 
placed in the hardening vessel, H. The supply pipe ter- 
minates below the water-level, and the water flowing from 



94 



TOOL-STEEL. 



it carries along (juantities of surrouiuling water and con- 
veys them to tlie area to be hardened. For the support of 
the tool, W, to be hardened, a grate, li, extending below 
the surface of the water, is fitted to the hardening vessel 
(see Fig. 51). When it is not feasible to support the tool 
upon the grate, for fear that the area to be hardened may 



Fig. 51. 



P^io. o2. 





remain soft on the places which come in contact with the 
grate, it must be held with the tongs Z, and suspended free, 
as shown in Fig. 52. The tool to be hardened remains 
exposed to the ascending water-jet until it is cold, it being, 
of course, immersed to a sufficient depth. The more vigor- 
ous the flow of water is, the better the hardening will turn 
out. 

For tools, the entire bulk of which is to be hardened, but 
which are of such large dimensions as to make even cool- 
ing by moving them in the hardening water no longer 
possible, special devices are required for the uniform con- 



COOLING OF TOOLS IN HARDENING. 95 

veyance of the hardening fluid from every side to the tool. 
A brief description of such devices for hardening balls and 
rolls will be found in the Appendix. 

The method of hardening by means of a jet may also be 
employed, if the operation of hardening, as is customary in 
some factories, is not effected in pure water, but in a large 
reservoir which contains a sufficient quantity of water 
compounded with salts or acids to allow of a large number 
of tools to be hardened without its temperature being essen- 
tially raised. To be sure special small pumps are then 
required, which for occasional use may be worked by hand 
while for continuous working power is required. The ad- 
vantage of the use of such pumps is that the lower cooler 
layers of the hardening bath are brought to the surface, 
the temperature of the bath being thus equalized. 

Hollow bodies which are to be hardened inside, or inside 
and outside, require special devices so that cooling may 
take place without uneven hardening being caused by the 
development of steam. 

Tools, entirely bored through or hollow, are cooled by 
conducting a powerful jet of water through the interior. 
If the surface is also to be hardened it must be cooled by a 
simultaneously acting water jet. 

Fig. 53 shows the operation of hardening from the inside, 
and Fig. 54 from the outside and inside. These devices 
require small power plants. 

The hollow body H is placed between two pipes, a b, 
Fig. 53. The pipe b is fitted movable to the pipe c so that 
the hollow body H can be firmly wedged between the two 
pipes. A supply cock being at the same time opened, 
water under high pressure enters and in passing through 
the hollow body hardens its walls. 



96 



TOOL-STKEL. 



Fig. 54 shows the hollow body also sinrouiidod by a 
movable pipe d. By closing the pipes h, c jind d, the water 
flows through between them and hardens the surface and 
interior of the hollow body. In place of the additional 
pipe d, the surface may also be cooled by direct-acting 
roses. 

Cooling the interior of a hollow body which is not en- 



Fig. 53. 



Fig. 54. 



Fig. 55. 




tirely perforated, presents greater difficulties, and the more 
so the narrower and deeper the opening is. Hardening is 
then effected by the direct introduction of as powerful a jet 
of water as possible. If the size of the aperture allows of 
the introduction of a pipe, one end of which, corresponding 
to the depth of the aperture, is provided with numerous 
small holes, even hardening is readily obtained with a 
powerful pressure of water (see Fig. 55). 



LIQUIDS USED IN QUENCHING STEEL. 97 

XII. 

LIQUIDS USED IN QUENCHING STEEL. 
1. Pure Water. 

EoR quenching steel for the purpose of hardening, pure 
water is mostly employed, and the colder it is the more in- 
tense the hardening will be, and the less so the warmer 
it is. 

The most suitable temperature of the hardening water 
lies between 60° and 72° F. Colder water will not appre- 
ciably increase the hardening eflect, but decreases the 
toughness of the steel, the latter becoming very brittle. 

It may be laid down as a rule that the larger the cross- 
section of the tool to be hardened, the lower the tempera- 
ture of the water must be. For large tools a temperature 
of over 65° F. should not be used. Small, especially thin, 
tools will take sufficient hardness at a temperature of the 
bath of about 86° to 95° F. The temperature of the hard- 
ening water must also be chosen in accordance with the 
form and size of the tool, as well as the degree of hardness 
desired. 

Chemically pure water, i. e. water which does not contain 
other substances, does not exist in nature, and its chemical 
composition varies very much, it containing soluble and in- 
soluble mineral salts and acids in a state of minute division. 

Many salts and acids increase the heat-conducting power 

of water and hence bring about more intense hardening, 

while earths and other mineral substances in the water have 

a detrimental effect in this respect. It is for this reason that 

7 



98 TOOL-STKKI,. 

pure well or spring water wliicli chiefly contains acids and 
carbonates in solution will harden more sharply than river 
water (especially when turbid) or water containing lime. 

In order to lessen the too intense hardening effect of well 
or spring water, some soda or potash may be dissolved iu 
it ; and to impart better hardening qualities to river water, 
it is mixed with small quantities of acids (hydrochloric acid, 
sulphuric acid, vinegar, etc.). Experienced hardeners place 
great value upon the favorable effect of hardening water 
which has been used for some time, and are very unwilling 
to renew it, because it is claimed to improve in quality, 
i. e., it hardens well and mild. The reason for this has to 
be found in the fact that fine particles of undissolved ad- 
mixtures gradually separate on their own account and sink 
to the bottom, while by the action of the hot steel which is 
plunged into the water, soluble substances are gradually 
removed by evaporation as well as by conversion into in- 
soluble substances, the latter being partially precipitated 
upon the surface of the steel. Hardening water which has 
been used for some time will finally get into such a condi 
tion that the unintentional admixtures have become harm- 
less, and hardening in it always yields uniform results. 

If this condition is to be brought about from the start, 
the water should be boiled before its being used for harden- 
ing, or it maj', so to say, be sterilized by quenching in it 
larger quantities of hot pieces of iron. 

2. Hardening Water Mixed with Soluble 
Constituents. 

Soluble admixtures, as previously mentioned, exert great 
influence upon the action of the hardening water, their 



LIQUIDS USKl) IX (iUENCHIXG STEEL. 99 

efl'ect being either an intensifying one, if the heat-conduct- 
ing power of the water is increased, or a moderating and 
retarding one, if the heat-conducting power of the water is 
decreased, or the boiling point is essentially lowered. 

Common salt is mostly used as a soluble admixture for 
increasing the heat-conducting power. It is dissolved in 
varying proportions by weight, though generally a saturated 
solution of it is used. The latter may be recommended 
whenever tools of complicated shape which are to possess 
great hardness are to be hardened in large numbers or in 
rapid succession. 

In using such cooling fluid, it must be borne in mind 
that the bath must be of sufficient volume so that its tem- 
perature is not essentially raised by continuous hardening. 
A vessel of as large a size as possible should therefore be 
selected for the reception of the bath, and it is better to use 
a shallow vessel of large diameter than a narrow and 
deep one. 

Soda (carbonate of soda) and sal ammoniac dissolved in 
water do not produce such an intense effect as common 
salt; but though they are more seldom used they are excel- 
lent admixtures to hardening water, particularly for compli- 
•cated tools, especially for cutters, a superficial separation of 
some parts of which may be feared. 

Acids in particular intensify the action of the hardening 
water in a much higher degree than common salt. They 
may be added in quantities of up to 2 per cent., sometimes 
in combination with salts. Organic acids (acetic, citric 
acids) produce a milder effect than mineral acids (hydro- 
chloric, nitric and sulphuric acids). 

Acidulated water is used for tools which are to possess 
L.of C, 



1 00 TOOL-STEEL. 

the highest attainable degree of hardness (cutters for work- 
ing articles of special hardness), or for giving a surface of 
sufficient hardness to steel which does not possess good 
hardening qualities. 

Alcohol lowers the boiling point of water and, when the 
latter comes in contact with the hot tool, causes such an 
energetic evaporation that hardening is more or less re- 
tarded according to the strength of the mixture. Water 
which contains a large proportion of alcohol does not 
harden at all. 

Soap. Soap water does not harden steel, and this prop- 
erty is made use of for rapidly quenching steel when the 
latter is not to be sufficiently hardened by cooling. When 
some parts of a tool which has been entirely hardened are 
to be made soft, they are brought to a red heat and cooled 
in soap water (tangs of files, knives, sabres, saws, etc.). 

Soluble admixtures of organic nature retard hardening 
more or less according to the proportion of admixture, and 
hence modify the action of pure water. In practice they 
are rarely used and then only in small quantities, for in- 
stance, milk, sour beer, etc. 

3. Hardening Water Mixed with Insoluble Con- 
stituents. 

Such water is frequently used for hardening especially 
complicated tools to protect them against cracks. For its 
preparation, lime in the form of milk of lime is chiefly em- 
ployed, clay or loam being more seldom used. Such water 
has a more or less retarding effect according to the strength 
of the n)ixture. The admixed constituent being intimately 
incorporated with the water, is precipitated upon the hot 



LIQUIDS USED IN QUENCHING STEEL. 101 

steel when the hitter is plunged into the bath, and forms upon 
it a thin layer which prevents direct contact of the steel with 
the hardening water. Cooling thus takes place more slowly, 
and by reason of the retarding effect, the hardening is less 
intense in character. 

4. Hardening Water Mixed with Oils or Fats. 

Oils and fats harden with considerably less intensity 
than water. The degree of hardness obtained with them is 
the less the larger the cross-section of the tool, and also the 
more viscid the oil or fat used. When a tool is to be given 
a higher degree of hardness than is possible with oil or fat 
alone, the surface of the water is coated with a layer of it 
and the tool plunged through it in the water below. The 
tool is thereby less rapidly cooled at the first stage, as it 
has become coated with a skin of fat toughened by the heat 
which retards the further cooling in the water below. The 
thicker the layer of fat or oil upon the water is and the more 
slowlj^ the tool is plunged through it the less the degree of 
hardness will be. For hardening cutting tools which are 
to hold their edges when employed upon hard materials, 
the use of water covered with oil or fat requires consider- 
able experience and great skill if uniformly good results 
are to be obtained. For such tools which are to be hard- 
ened all over, the use of milk of lime or the mode of hard- 
ening described on p. 76 is to be preferred. On the other 
hand, tools which must possess a tougher degree of hard- 
ness, for instance, cutters for wood, disc knives, circular 
shear knives, etc., may be hardened to advantage in water 
covered with a layer of oil. 



102 tool-steel. 

5. Oils and Fats. 

Oils and fats, as previously mentioned, possess, according 
to their consistency, less hardening power than water. The 
hardness produced by them is mild with great toughness. 

Thin tools, which readily crack during the process of 
hardening and which do not require the highest attainable 
degree of hardness, are hardened in oil or fat. Of the oils, 
petroleum hardens with the greatest intensity ; next glycer- 
ine, which heretofore has not been sufficiently appreciated 
as a hardening fluid ; then light mineral oils, and finally 
viscid vegetable oils, for instance, linseed oil. 

Amongst fats, melted tallow and train oil are most fre- 
quently used. A somewhat higher degree of hardness is 
obtained in melted tallow than in oils. 

In using fat or oil for hardening, it should be borne in 
mind that a sufficient quantity of it must be employed to 
allow of the article to be hardened to be vigorously moved 
in the bath during cooling, the same as in water, and that 
no rise in the temperature takes place during the operation 
of hardening. Too small a quantity of oil or fat is, as a 
rule, employed in practice, and non-success in hardening is 
then put down to the bad hardening qualities of the oil or fat. 

6. Metals. 
Mercury of all the metals possesses the greatest power of 
conducting heat and exerts the most energetic hardening 
effect. It is, however, seldom used and then only for hard- 
ening very small tools. It readily volatilizes and for hard- 
ening larger tools would have to be employed in consider- 
able quantities. The high price of the metal and the losses 
in hardening by volatilization are out of all proportion to 



LIQUIDS USED IN QUENCHING STEEL, 103 

the advantages derived from its use. The vapors formed 
in hardening by the volatilization of mercury are of the 
same poisonous nature as the metal itself. 

Im, zinc and lead and their alloys in a melted state may 
also be used as cooling agents. However, their melting 
points lie so high that actual hardening in them does not 
take place to the same extent as in the previously-described 
cooling agents. The properties of steel cooled in melted 
metals also undergo a change, its strength being considerably 
increased, and it becomes so hard that it can be worked 
only with difficulty or not at all. It possesses, however, 
but little cutting power. Its elasticity is also increased. 

The hardness of the steel is still further increased if the 
tool after having been immersed for a short time {I to 2 
minutes according to its cross-section) in the melted metal, 
is very rapidly cooled in water. 

This process of hardening is suitable for springs as well 
as tools to be used for working soft materials, and to which 
the necessary tough hardness aud cutting power are to be 
given without first tempering them after hardening, as is 
frequently desired in manufacturing on a large scale. 
Further, for giving the necessary properties to machine 
parts subject to great demands as regards strength and 
wear. 

In using melted metals it is of importance that the same 
degree of temperature be constantly maintained. Hence 
adequate quantities of them must be used, proper heating 
devices provided, and the temperature tested with a pyro- 
meter. 

Further details, especially as regards the devices em- 
ployed in the manufacture of tools on a large scale, would 
carry us too far. 



104 tool-steel. 

7. Gaseous Cooling Agents. 

Tools of small cross-sections may be hardened by a sharp 
cold current of air. However, the use of air or gases for 
hardening is a very limited one, and not very reliable in 
practice. l*'or hardening of tools in general it is of no im- 
portance. 

8. Solid Bodies as Cooling Agents. 

Solid bodies of good heat-conducting power may find 
practicar application for hardening very thin tools. Pieces 
of wood thoroughly saturated with water between which 
the thin tool is laid for the purpose of hardening are seldom 
used, but hardening is more frequently effected, especially 
in the manufacture of saws, between iron plates which are 
constantly cooled by an uninterrupted stream of water. 
The tools while between the iron plates being also subjected 
to pre^ure, this method of hardening is also termed " hard- 
ening by pressure." It is especially applicable to the con- 
tinuous hardening of band-steel, and to the manufacture on 
a large scale of thin tools which are to acquire during the 
operation of hardening a tough serviceable degree of hard- 
ness. 

Moist sand and clay also effect hardening, but it is diffi- 
cult to obtain an even hardness by their use. 

The cooling agents described above may, of course, be used 
in any combination desired by effecting cooling in succes- 
sion in two, or more seldom in three, fluids differing in 
action. The process most commonly employed is to harden 
in water until all glow has disappeared and subsequently 
allowing to cool completely in oil or hot water. 

By frequently repeated experiments regarding the cutting 



LIQUIDS USED IN QUENCHING STEEL. 105 

power of medium hard tool-steel hardened in various cool- 
ing agents, the following results were obtained in Bismarck- 
huette : 

Steel with 1 per cent, carbon. 

Hardened in oil, efficiency attained 100 

Hardened in tallow, efficiency attained 108 

Hardened in pure water of 65° F., efficiency attained 133 

Hardened in water with 1 per cent, sulphuric acid, efficiency attained . • • 140 

From the relative proportions of these figures, a conclu- 
sion may be drawn as to the effect of the different harden- 
ing fluids used. 



XIII. 

TEMPERING OF HARDENED STEEL AND 
DEVICES FOR THIS PURPOSE. 

The main points in regard to tempering of steel have 
T^een referred to on p. 22, and the table found there. 

Tempering may be effected in either one of three ways, 
namely : 

1. By not allowing the hardened steel to cool entirely, 

but to effect tempering by utilizing the heat present 
in the interior of the tool or in a portion of it, as it 
progresses towards the hardened part. 

2. Cooling off the tool entirely in hardening, and effect- 

ing tempering from the outside. 

3. By tempering the tool from the interior and assisting 

the progress of the heat from the exterior. 
Tempering from the interior is effected with all kinds of 



106 TOOI.-STEEL. 

tools which liave been partially hardened and in which the 
heat stored back of, or inside, the hardened portions is 
allowed to progress towards them, for instance, turning 
knives, hand chisels, hot and cold chisels, milling tools, 
drills, tools for working stone, etc., or swages, cutters, 
hammers, etc. 

To be able to recognize the advance of the heat by the 
progression of the tem{)er colors, the hardened tool is 
rubbed bright, and should the heat advance unevenly, the 
respective portion is cooled by immersion for a short time 
in water. 

When the tool shows the desired temper color, it is 
gradually cooled by being repeatedly plunged for a short 
time in water. 

To impart special toughness to a tool which in use is ex- 
posed to shock and blow% it may be repeatedly tempered by 
rubbing off the first temper color and again producing it. 
For cutting tools this method may unhesitatingly be re- 
commended especially with the use of harder steel and 
when the tools in use are exposed to rebounding blows, as, 
for instance, hot and cold chisels, which in notching rails, 
beams, etc., are subject to vigorous blows with heavy ham- 
mers ; further, riveting punches and different tools used in 
structural work. Tools to be partially hardened, which 
have been cooled too far back of the edges, snap readily 
after having been tempered, in consequence of some por- 
tions of them not possessing a sufficient degree of toughness, 
especially if the cutting parts work under high pressure, 
for instance turning knives, or are subjected to shock and 
blow (chisels, drills, etc.). 

When tools partially to be hardened have not been hard- 



LIQUIDS USED IN QUENCHING STEEL. 107 

ened far enough back of the edges, the}' possess an insuffi- 
cient degree of liardness, and the operation has to be re- 
peated. Tools which show the required degree of hardness 
only on the edges crack readily in use when subject to pres- 
sure and shock, the cracks running in a perpendicular 
direction to the edges. The material lying immediatelj'' 
back of the edge, and which is mostly of a smaller cross- 
section, is upset and the hardened edge tears in consequence 
of not possessing sufficient toughness 
to follow the change in form. 

The progression of such cracks R is 
sketched in Fig. 56. 

Tools which have been entirely 
hardened are seldom tempered from 
the interior, the process being as 
follows : 

The tool, according to its thickness, 
is cooled only long enough for the surface to become cold, 
and so that sufficient heat remains stored in the interior 
which, in its progress toward the exterior, causes the previ- 
ously hardened surface to be tempered. 

However, since by this procees the heat advancing from 
the interior does not, as a rule, arrive at the same time at 
all portions of the surface, the result will be an uneven de- 
gree of tempering, and is difficult to judge by the progres- 
sion of the temper-color, because in the short space of time 
at the disposal of the workman it is generally impossible to 
brighten every portion of the hardened tool. 

If tools are hardened in water and then allowed to cool 
in oil, tempering from the interior results very uniformly, 
because the surrounding oil cools off the portions where the 
heat may advance too energetically. 




108 TOOI.-STKKI,. 

I( iiiusl. lu»U(>V(M', he Imhiic ill iiiiiul lliMl Irctiuciil ly the 
lifjit (lot's not jkIvmihc with siiliicit-nl rapidity liom tlif in- 
(nior to iiu'fi>Mst' at tlu> proptM- tiiiu' the toiiuliiuss of tho 
hjiriloiu>(l s(ot>l mIomo i\\v lino o\' \vi\M stivii>;tli — hotwcon 
tlu' hard sludl and th(> mild hard cow. It may then 
happrn that a scvtMaiu'c of tho hardonod surface, or [)or- 
(ions of it, rosiilts hofoic tomporinii is otUH-tiHl ; iho water 
in this i'asi> haviiii; oooKmI tho to«>l too nnioh proviously to 
its having Iuhmi hrou^ht into tho oil. 

This (Irawhat'k may ho ohviatod hy assisting toni[)oring 
from tho interior hy sinniltanoons lu>atinu- from tho outside, 
as iiosorih(>d o\\ pauo 7(>. ('oolinu I'an thon ht^ oll'ootod to a 
suHiciont doi>th to provont softi-ninu,- hy sul>so(iuont lotting- 
iit>\vn. and tho surt"ao(> thus prt^ootod from oraoks. 

Tools thus tomjH'riMl aro. howovor. nn>stly usod with tho 
full doi;ri>o o\' haidnoss altaiuiMl without stithniui: hy fur- 
ther teniporing from tho outsido. 

AttenticMi may horo ho drawn to an error whioh is fre- 
(]U(>ntly committed. In 0(Mn}detoIy coolinii hardono(1 and 
tomjxMvd tools they slunild hi> unit'ormly surrouniUil hy tho 
cooling tluid. wlu>thor tho latter he oil or water. A mis- 
take is tVtH|uently made in layinu tho hardiMUMl ti>ol (or tho 
purpose of oooling upon tho hottom oi' tho vessel containing 
the cooling Huid. Ou tho }>lace of contact hotwoon the side 
of the vessel and the tool, the latter, for reasons which can 
be readily understt)od. hoeomes softer than in other places, 
lloui-o the tool should ho suspended in the tluid. 

Tools of sm.all oross-sootitms whioh cannot ho tempered 
during the hardening operation .-ire hardened entirely, and 
immediately after this operation aro brought into hot water, 
or somewhat reheated in hot sand, io avoid the formation 
of cracks after hardening. 



MC^IUDS nSKI) IN t^mON('IIIN<i STKIOI;. 109 

'l"('inji(Miii<; of li.'ir<l('iH'(l tools iiiay iilso Ix^ cMccNmI ovci' a 
iModcriilcly liol cIuircoMl lire, upon hot sniid, of in nioIUm 
inetalt^, etc. 

fn f(>iu])('iiii^ from tlu' outside it must, \)v boiiu; in inind 
tlijit, Ity icason ol' l.lu>ir slighter tliicknoss, jn'ojeciin^ por- 
lio!is ol' tools, cuttcM's, etc., may Ix' readily heated too much 
and lose more hardness than originally intended. Ileiieci, 
teiiiperin<^ should not he undertaken at a ^reali^r heat, than 
necessary lor biinj^iu}:; out the ttanper coloi-. 

A very uneven aj)|)earanee ol the tem|ier color is an in- 
dication of too rapid or uneven jieatin^. in handling 
tools with lon^- ed^cs the temper color fre(|Uently does not 
progress with uniroiniily in eonseciuciice of uneven lieatin;j;. 
The portions which have heeome heated too soon are then 
cooled ofl' with moist rags or- by sprinkling with wat(!r until 
the ten»j)er color has progressed with unilormity in the 
other portions. 

Longer tools, one end of which is t<» be liaid while th<; 
hardness is giadually to dettrease towards the outer end, ai'o 
tempered by heating veiy slowly the end which is to 1)0 
softer. Tlie temper colors then apjx'ar at longer intervals, 
and, as the heat spreads, can gradually pi'ogress towards 
the outer end of the tool. 

^I'he temf»ering ol" tools i('<|uii'es above all uniform heat- 
ing, just the sam(^ as in hardening. The degicc! of luiat 
attained can, however, be readily judged by the progicssion 
of the temper colors, and hence great attention rather tluin 
skill is nHjuired for the operation. 

The space of time in which tempering results is also of 
great inlluence upon the degree of toughness attained by 
the steel. Th<' moie slowly tempering is eU'ectt'd, the more 



110 TOOL-STEEL. 

evenly tlie lioat will be distributed over the entire cross 
section of the tool, and tlie greater the degree of toughness 
will be which the tool acquires. 

As will be seen from Table II, (facing p. 22), with 
rapid heating the yellow temper color appears when the 
tool has acquired a temperature of 442.4° F. By exposing 
the tool for a longer time to tlii.s temperature every temper 
color up to dark blue aj)])ears one after the other without 
the tool having been heated to a higher temperature. The 
smaller the cross section of a tool is, the more rapidly the 
temper colors appear. 

A similar phenomenon may be observed when hardened 
tools are for some time laid in boiling water, their tough- 
ness being thereby materially increased while their hard- 
ness is reduced. 

This })henomenon is of practical importance when tools 
are to be tempered in molten metals, because with the use 
of one and the same bath of fixed temperature different 
degrees of touglniess and hardness can be obtained, accord- 
ing to the length of time the bath is allowed to act. The 
metal bath must of course be jirovidcd with a })yrometer, 
iind the duration of immersion accurately regulated. 

This process is practically applied in manufacturing on a 
large scale, especially in tempering the back portions of 
projectiles, etc. 

Springs are in many cases tempered by what is termed 
blazing off with oil. The hardened spring is brushed over 
with oil and heated until the oil inflames and burns off. 
In manufacturing on a large scale this process, however, is 
but seldom emjdoyed, because tempering in a muffle heated 
to a dark-brow^n heat is cheaper and the result more uni- 
form and assured. 



LIQUIDS USED IX QUENCHING STEEL. 



Ill 



Small tools which are to possess the hardness of a spring 
may be tempered in an oil which may be heated to 554° 
F. before it inflames. For this operation the oil is heated 
in an iron vessel containing the articles to be tempered 
until it commences to bubble. The vessel is then quickly 
covered with a close-fitting lid, removed from the fire and 
allowed slowly to qooL 

This mode of tempering is very suitable in manufacturing 
on a large scale if devices are provided by means of which 

Fig. 57. 




the rise in the temperature of the oil can be closely watched 
so that the oil is heated to near the inflaming point, but 
never up to it, or even above it. 

The device shown in Fig. 57, which is of French origin, 
answers the above-mentioned requirements. 

An iron kettle A is heated by a gas flame (illuminating 



112 TOOL-STEEL. 

gas) SO arranged that it can be readily turned oil. A small 
perforated vessel a which fits in the kettle and reaches 
nearly to the bottom of the latter serves for the recei)tion of 
the tools to be tempered. The bipartite lid d is secured by 
means of screw clamps. From one part of the cover, a 
pipe R leads to a vessel filled with water which serves for 
condensing the oil vapors or for carrying of!" oil boiling 
over. This part ol" the lid also contains the pyrometer P. 

The oil is heated to about 500° F. and allowed to remain 
at this temperature for an accurately measured length of 
time. The gas flame is then turned off and the kettle 
allowed slowly to cool, or the tools are taken from the oil 
and a fresh supply of tools is introduced. 

In reference to the devices for tempering it may be 
added that they must be adapted as much as possible to the 
demand for uniform heating of the tools. Even with tools 
only partially to be tempered, the heat must evenly extend 
over the portion to be tempered. 

Tempering may be effected in an open fire ; a bright 
glow or sooting flame must however be avoided, and 
eventually a piece of sheet iron is placed between the tool 
to be tempered and the fire. 

For tempering smaller tools red hot iron is niostl}^ used, 
it being brought into close contact with the surface to be 
tempered. 

Perforated tools are tempered by pushing a red hot 
mandril into the bore. 

Disc-like tools are placed between red hot iron plates of 
smaller circumference than the tools. 

Tempering is frequently eflected by means of a gas flame 
which, however, should not be pointed. 



LIQUIDS USED IN QUENCHIN<J STEEL. 



113 



Tempering by means of hot sand may be effected with 
the use of an open fire by heating the sand upon sheet-iron 
and then tempering the tools in it. For tempering larger 



Fig. 58. 




tools, or a number of them a special furnace, as shown in 
Fig. 58, may be used. 

A perforated iron plate kept constantly red hot may be 
used in a similar manner. The tempering furnace may 
then be constructed like an ordinary kitchen hearth. 
8 



114 



TOOL-STEEL. 



Partial tempering of tools in molten lead may be recom- 
mended for the purpose of producing a degree of hardness 
running very evenly from one end to the other. 

The portion of the tool which is to be entirely tempered 
is immersed in the molten lead, which causes it to be 
heated very slowly and evenly. The temper colors progress 
uniformly on tlie portions of the tool outside of the lead. 

Tempering of large tools which have to be evenly heated 
in the direction of their length requires special devices to 
obtain a uniform tempering temperature. A furnace which 
serves for tempering long knives is shown in Fig. 59. 



Fig. 59. 












=^ -■ .-_ 


,^ 




— - 


■ 




U*i**4i-**^ 


JL ^l..J 













^ 



A sheet-iron box 7' of trapezoid cross-section rests upon 
iron legs F. In place of a bottom it is furnished with iron 
rods R forming a grate. The interior of the box is lined 
with thin fire brick or with fire clay. The knives ilf to be 
tempered rest upon a few cross rods o over the upper por- 
tion of the box. The whole is closed with a sheet-iron 
cover B which is provided in the centre, in the direction of 
its length, with an opening for the escape of the gases. 

For use, glowing charcoal is evenly distributed over the 
grate R and upon this is placed fresh charcoal the size of a 
nut. When all the charcoal is in full glow, the knives are 
placed in position as shown in the illustration and tem- 
pered. 



LIQUIDS USP:D in (iUENCHING STEEL. 



n5 



The small furnace, above described, should be placed in 
a room in such a manner as to prevent the possibility of 
the charcoal burning unevenly by reason of draughts. If 
the charcoal burns less bright in some places than in others, 
it may be remedied by blowing with a hand bellows or by 
pushing pieces of sheet-iron below the grate at the places 
where the fire is too bright. 

Fig. 60 shows the same furnace constructed of brick. 



Fm. 60. 




In order to be sure of the production of a uniform heat 
an air chamber may be fixed beneath the grate, the air be- 
ing introduced by means of a perforated gas pipe (see Fig. 
59). This may in a similar manner be done with the brick 
furnace, Fig. 60. 

The temper of the steel is fixed by either quenching 
rapidly from the temperature attained or by allowing 
slowly to cool. 

The tempered tool may be allowed slowly to cool if it did 
not contain more heat than was required for tempering. 

If the tool had been partially heated, more than neces- 
sary for tempering, it must be rapidl}- cooled to prevent 
softening. 

Cooling may be effected by plunging the tool in rapid 
succession in water or allowing it slowly to cool in mild 



116 TOOL-STKKL. 

oils or fats. If hardening of portions of the tool which are 
still at the hardening temperature is to be avoided, the tool 
for the purpose of fixing the temper is plunged in soap 
water. 

In tempering partially hardened tools an error is fre- 
quently committed in heating them too far back of the 
edges, and for the purpose of cooling placing the tools — 
which in themselves are properly hardened and tempered — 
with the edges foremost in shallow water. The heat pene- 
trating from the too highly heated portions towards the 
hardened parts standing in the water causes a sharp boun- 
dary to be formed between the hardened and unhardened 
parts, and along this boundary the edges are sure to break 
off. This error may be avoided by first plunging the tools 
in soap water to withdraw from them the highest heat. 
The above mentioned error is frequently made in hardening 
hand chisels, hot and cold chisels, drills, rock drilling 
tools, etc. 



XIV. 

STRAIGHTENING TOOLS. 

Tools which have become distorted in hardening cannot 
be straightened while in a cold state without danger of 
breaking them. Hence this operation is, as far as possible, 
combined with that of tempering, because the steel while 
still in a heated state possesses sufficient plasticity to allow 
of being straightened. 



STRAIGHTENING TOOLS. 117 

Straightening the steel may he effected : 

1. By pressure. 

2. By bending and twisting by means of straightening 
claws. 

3. By blows with the straightening and chasing ham- 
mer. 

4. By uneven heating and cooling during tempering. 
The distortion of tools during hardening is, in most 

cases, caused by uneven heating or uneven cooling, and 
tools of a slight cross-section and greater length or width 
are more frequently affected than tools of a larger cross- 
section. Uneven cooling causes uneven changes in volume, 
and consequently the steel becomes distorted. 

Tools which have undergone hardening by pressure are 
straightened during the operation of hardening, i. e., their 
becoming distorted is prevented during cooling. 

Thin, flat tools which cannot be readily straightened 
with the hammer are firmly clamped, whilst in the temper- 
ing temperature, between two hand-warm iron plates and 
allowed to cool. 

Long tools of symmetrical cross-section — for instance, 
twist augers, broaches, etc. — are straightened under a hand- 
warm screw-press. 

Flat tools which become easily distorted in hardening 
are straightened by means of straightening-claws imme- 
diately after tempering or during that operation. 

For the purpose of straightening, one end of the tool is 
clamped in a vice while the other end is gra.sped with the 
straightening-claw, and the tool is slowly twisted straight. 
In simple cases two straightening-claws may be used. 
Such straightening-claws are easily made by bending one 



118 



TOOL-STKKI.. 



Fig. 61. 




end of an iron bar, as shown in Fig. 61. For the i)urpose 
of straightening the tool is laid in the clefts *S'. 

Tools distorted to an undulatory 
or crescent-shaped form can be 
straightened only with difficulty 
by pressure, and not at all by 
means of straightening claws. 
Straightening must then be ef- 
fected by blows, which requires 
much skill and experience. 

The tools required for this pur})ose are as follows : 

A straightening anvil, i. e., an anvil with a large some- 
what convex face whicli should be smooth and thor- 
oughly hardened. 
A straightening hammer, i. e., a copper hammer with 
two broad faces of different convexity, and a steel 
straightening hammer with a broad convex face and 
a narrow sharply rounded face which stands in the 
direction of the hammer-helve. 
The blows with the hammer should always be given on 
the hollow side of the tool. If vigorous blows with the 
flat side of the hammer do not suffice, the sharp face has to 
be applied, the latter producing a powerful drawing-out 
effect in the vertical direction towards the edge. Blows 
incorrectly applied readily cause worse distortion of the 
tool. The short time the latter remains in the suitable 
temperature requi4'es quick and sure work. 

Straightening of tools by uneven heating and cooling in 
tempering or when the tool is cold, can onl}' be done in 
rare cases and when the tool is but slightly distorted. 
Such tools are laid, hollow side down, upon the temper- 



CASE-HARDENIKG. 119 

ing furnace or on a hot iron plate, and cooled upon the con- 
vex side until they have become straight. 



XV. 

CASE-HARDENING AND PREVENTATIVES 

AGAINST SUPERFICIAL DECARBON- 

IZATION AND OVERHEATING. 

The process of case-hardening or surface-hardening is 
made use of if steel with but little capacity for hardening, 
or iron not capable of being hardened, is to be supplied with 
a hard surface, the object being attained by cementation. 

If iron is for some time heated in intimate contact with 
substances rich in carbon and which readily yield it, it ab- 
sorbs carbon, the latter penetrating the further from the 
surface towards the centre the higher the temperature is, 
and the longer heating has been continued. The carbon 
absorbed during lieating imparts to the iron the capacity of 
being hardened, or increases that of steel capable of being 
but slightly hardened. 

When heating with carbon is effected at a high tempera- 
ture and for a longer time, the structure of the steel or iron 
undergoes a change, it becoming coarsely crystalline, and 
the cohesion between its particles is loosened. The conse- 
quence of this is a brittle shortness which is increased in 
the hardened state if the fine structure is not previously re- 
stored by forging. Hence to avoid failure as regards the 
quality of the product, the temperature should not be too 
high nor heating continued too long. 



120 TOOL-STEKL. 

By case-hardening a layer of the tool extending to a 
greater depth is rendered harder. A tool of a smaller cross- 
section may even have ahsorbed carbon throughout and 
have become capable of being hardened. 

It is not always desirable to impart to tools a hardness 
penetrating to a greater depth, a very superficial higher 
degree of hardness being frequently only required, and this 
is obtained by so-called " burning in." 

The method pursued in the operation of case-hardening 
is as follows : 

The tools are packed in an iron box with charcoal 
powder so as to be uniformly covered on all sides. The 
box is then covered with a tightly fitting lid, and after all 
the joints have been made air-tight by daubing with clay, 
it is placed in the muffle of a muffle furnace, or in an 
annealing furnace (see Fig. 20). Heating to a uniform 
temperature is effected in the same manner as in annealing, 
and the box is kept at this temperature for a longer or 
shorter time, according to the degree of hardness desired. 
The heat should not exceed a bright cherry-red, otherwise 
the tools may readily be ruined. As a rule the tools are 
at once hardened at this temperature and are but seldom 
allowed to cool and then reheated for hardening. 

In practice case-hardening is resorted to in the manu- 
facture on a large scale of tools or machine-parts which for 
the sake of cheapness are made of wrought iron or have 
been cast, for instance, for sewing machines, parts of 
bicycles, tools forming constituent parts of household 
utensils, and even scissors, knives, hatchets, etc. The 
carbonaceous substances employed are used either in a pure 
state or mixed according to their efficiency as found by ex- 



CASE-HARDENING. 



121 



perience. When charcoal is used, preference should be 
given to that of linden or bass-wood ; soot is less frequently 
employed and has no advantage over charcoal. Charcoal 
obtained by charring animal substances, such as leather, 
horn and bone, is very much liked for case-hardening, 
charred leather being preferred above all, since experience 
has proved it to be most efficacious. 

Animal substances dried and ground to powder, or cut 
up in shavings, for instance, horn and hoof powdered or in 
shavings, glue, etc., are milder in their action, do not 
cement so rapidly as charcoal, and require longer time for 
heating. Hence they are but seldom used for case-harden- 
ing, but frequently as a })rotection of the surfaces of larger 
tools, to avoid superficial decarbonization or to withdraw 
them from the direct action of the fuel. 

Tools to acquire an even degree of hardness by case- 
hardening must be free from adhering foreign substances, 

Fig. 62. 




i. e., must have a pure metallic surface, and hence have to 
be scoured before being placed in the box. 

If certain portions of the surfaces of the tools are to re- 
main soft, they are protected from cementation by coating 
them with a claj' paste or packing them in substances 
which yield no carbon (sand, brick-dust, etc.). 

Fig. 62 illustrates the manner of packing a spindle which 
is to be hard in two places. The spindle packed as shown 



122 TOOL-STEEL. 

in the illustration is for several hours exposed to a bright 
red h-eat, then taken from the packing and hardened. 

" Burning in " requires the use of substances which yield 
their carbon with ease and rapidity when in contact with 
the tools at a higher temperature. According to experience- 
yellow prussiate of potash is the most effective agent. 
When brought in contact with the red-hot tool it liquefies^ 
and in this condition exerts a powerful cementing effect. 
The mode of operation is as follows : 

Heat the tool to a red heat and scatter yellow prussiate- 
of potash over the surface to be burnt in, it being best to- 
use a fine-meshed sieve for the purpose, so as to be sure of 
the even distribution of the salt. The tool is then returned 
to the fire, heated to the hardening temperature and hard- 
ened. For a greater depth of hardness on iron or very soft 
steel repeat the operation twice or three times. The surface 
of the tool must of course be free from scale. Very small 
tools which are to be given a high degree of hardness are 
treated as follows : 

Melt yellow prussiate of potash in an iron vessel over a 
moderate fire and bring the tool previously heated to a 
brown-red heat into the fused salt, and allow it to remain 
in it up to 15 minutes. The tool is then heated to the 
hardening temperature and hardened. 

With small, thin tools, a similar, though somewhat 
milder, effect is obtained by repeatedly bringing them to a 
red heat, slowly plunging them in oil or fat, reheating 
them each time, and finally hardening in water. If the 
effect is to be heightened, mix with the oil or fat (train oil}- 
sufficient soot or charcoal powder to make a pasty mass and 
plunge the red hot tool in the mixture. The tool becomes 



CASE-HARDENING. 123 

coated with a thick layer of the paste, which hums with 
difficulty and by subsequent heating efiects powerful 
cementation. 

By mixing flour, yellow prussiate of potash, saltpetre, 
horn shavings or hoof meal, fat and wax, a mass of paste- 
like consistence is obtained, which may serve for the same 
purpose. The different mixtures brought into commerce 
under the name of "hardening paste" are of similar com- 
position, and the ingredients may be chosen at will. For 
instance, melt : 

Wax 500 parts by weight. 

Tallow 500 " " 

Rosin 100 " " 

Add to the melted mass a sufficient quantity of equal 
parts of charred leather, horn shavings and hoof meal to 
make it of a paste-like consistence, then add 10 parts by 
weight of saltpetre, and 50 to 100 parts by weight of 
powdered yellow prussiate of potash, and stir thoroughly. 

The tools to be burnt in are plunged, while in a red hot 
state, in the paste, allowed to cool in it, again heated and 
hardened. 

A hardening powder to be scattered upon tools which 
are to be hardened after heating in the open fire, may be 
made of any desired mixture of yellow prussiate of potash, 
charcoal, rosin, calcined common salt, saltpetre, hoof meal, 
glass powder, etc. It must, however, be borne in mind 
that the only purpose of the substances which do not yield 
carbon, is to effect a better adhesion and uniform distribu- 
tion of the mixture as well as to destroy oxides (scale), and 
therefore the carbonaceous constituents must preponderate. 



124 TOOL-STEEL. 

The examples given below nuiy serve as illustrations of the 
composition of a dry hardening powder : 

Hoof meal 10 parts. 

Charred horn 10 '" 

Saltpetre ^ " 

Glass powder ^ ' ' 

Calcined common salt 2 " 

Yellow prussiate of potash 1 " 

In the manufacture of tools the agents for the production 
of a higher degree of hardness on the surface are of second- 
ary importance, it being generally preferred to use steel of 
such hardness as will allow of the degrees of efficiency 
required and which can be hardened without the assistance 
of hardening agents. 

Of greater importance, however, are agents for cooling 
tools which have been heated partially too rapidly or to 
too high a degree ; further, as a protection against contact 
with the combustion-gases or against partial decarboniza- 
tion in heating. 

Tools with sharply projecting portions on their surfaces, 
for instance, cutters, files, etc., can only with difficulty be 
heated to an even temperature without the corners and 
edges (teeth) becoming heated earlier, and finally to a 
higher degree, than the thicker bod3^ The consequence of 
this is that the edges acquire too brittle a hardness, further, 
cracks are formed, and with long continued over-heating, 
decarbonization takes place and the tools remain soft after 
hardening. 

In many cases, for instance, in hardening files, it be- 
comes necessary to protect the teeth from overheating and 
decarbonization, and with other tools, for instance, cutters. 



CASE-HARDENING. 125 

to cool them during heating when they have become hot 
too soon. 

Cooling of unevenly heated tools is effected by taking 
them from the fire and allowing them to cool in the air to a 
uniform temperature after which they are re-heated. The 
result of this process is, however, not always satisfactory, 
especially when there are considerable differences in the 
cross sections of the tool. In such case the use of a powder 
which effects cooling and prevents possible decarbonization 
may be decidedly recommended, and such powder should 
always be on hand when hardening complicated tools. A 
suitable powder is obtained by mixing the following in- 
gredients : 

Hoof meal 50 parts. 

Rye flour 5 " 

Common salt, calcined and powdered 25 " 

Glass powder 2 " 

Or, 

Common salt, calcined 1 part. 

Hoof meal 1 " 

Charred leather, pulverized 1 " 

Rye flour 1 " 

For use scatter the powder by means of a small shovel 
upon the portions of the tool which at the outset show a 
higher heat, or dip them in the powder, repeating the 
operation as often as necessar}'. The application of the 
powder is of use only with complicated tools. 

If the surfaces are at the outset to be protected, the tools, 
for the purpose of heating, are packed in a box between 
horn shavings and hoof meal, and heated together with the 
box ; or the tools, previous to hardening, are coated with 
a firmly adhering paste of carbonaceous substances. This 



126 TOOL-STEEL. 

coat is allowed to dry and the tools are then heated as 
usually for hardening. 

For this purpose, the mixtures given below, which are to 
be applied in a pasty condition, may be used : 

Cliarcoal or charred leather 1 part. 

Common salt 1 " 

Rye flour 1 " 

Or, 

Hoof meal 4 parts. 

Rye flour 1 part. 

Yellow prussiate of potash 1 per cent, by volume. 

Glass powder 1 " " 

Or, 

Hoof meal 2 parts. 

Charred leather 2 " 

Calcined horn meal 2 " 

Potassium chromate 1 part. 

Yellow prussiate of potash 1 " 

Rye flour 2 parts. 

The ingredients, previously reduced to a fine powder and 
intimately mixed, are made into a paste with concentrated 
common salt solution. The mixture is allowed to stand 
quietly for a few days, then thoroughly stirred, and for use 
applied with a brush to the tools, which should be pre- 
viously freed from adhering grease. To prevent the mass 
from peeling off when heated, it should be thoroughly dry 
before hardening the tools coated with it. 

The composition of the mixtures given above may, 
of course, be varied in any manner as desired and suited 
for the purpose in view. Only in rare cases is their use 
connected with any disadvantages, the principal of them 
being that the hardened tool shows a spotted appearance, 
due to the mass having in some places been burnt to it. 



WELDING OF STEEL. 127 

For case-hardening steel by cementation, carbon com- 
pounds in gaseous form are also used. If, for instance, 
illuminating gas is conducted over the surface of red-hot 
steel, it exerts a cementing effect of great energy, the sur- 
face of the steel becoming hard when rapidly cooled. 

This process is practically applied to armor-plates to 
which a hard surface is to be given. For this purpose car- 
buretted hydrogen, formed by the immersion of calcium 
carbide in water, is used. The gas is conducted over the 
surface of the red-hot armor-plate, the air being excluded. 

Pig iron is seldom employed for surface-hardening. It 
contains a high percentage of carbon, which it readily 
yields to iron or steel when it is brought into intimate con- 
tact with it, or when it is made to fuse on the surface 
of red-hot iron. The practical value of this mode of sur- 
face-hardening is very small, and the same result can, with 
greater certainty, be attained by case-hardening, or burn- 
ing in. 



XVI. 

WELDING OF STEEL. 

The operations in welding steel involve the overheating 
of the latter to a high degree, and consequently it may 
readily be burnt. It should be borne in mind that for 
welding, steel has to be heated to a less degree than iron, 
and only high enough to produce a pasty condition of the 
surface ; iron, on the other hand, may be softened to a 
greater depth. When steel is heated to a greater depth to 



128 TOOL-STEEL. 

a scintillating white heat, its stnu-tiiro loses its coherence 
to such an extent that in the subsequent forging the steel 
will crumble. 

The formation of a soft layer on the surface of the steel is 
an absolute necessity for welding. This state ot softness is 
obtained by bringing the steel to a bright yellow heat, the 
operation being assisted by scattering upon the steel agents 
readily fusible by themselves, and which protect the work 
from oxidation. 8uch agents are : Borax, fine quartz sand, 
clay, dried and pulverized or brick-dust, potash, soda, sal 
ammoniac, etc., which may be used in a mixture of any 
desired proportions. Borax and soda are fused before use 
and pulverized after cooling. 

The operation of welding is carried on as follows : The 
parts to be welded are carefully scarfed and fitted together. 
They are then brought to the welding heat, which for soft 
steel should be dark white, for hard steel bright yellowy 
and for iron scintillating white. The scale formed in heat- 
ing is scraped off, and shortly before attaining the welding 
heat, the welding powder is applied without, however, tak- 
ing the work from the fire. The work is then quickly 
taken from the fire ; the parts to be welded are pressed 
together, a superficial union is effected by light hammer 
blows, or still better by pressure. Welding powder is 
again scattered upon the weld, the work returned to the 
fire and again brought to the welding heat, which, how- 
ever, need not be so high as the first. 

Union is now effected by more vigorous hammer blows, 
and the finer structure of the steel is restored by forging 
continued as long as possible. To avoid the formation of 
cracks, the tool must next be allowed slowly to cool, and is 
then reheated for subsequent hardening. 



REGENERATION OF STEEL. 129 

If the weld does not turn out satisfactorily, the respective 
pieces have to be removed before repeating the operation. 

If, after welding, the steel shows edge cracks, it has been 
overheated and burnt ; or it is unsuitable for welding if, 
after carefully repeating the operation, .such cracks are 
still perceptible and the weld does not turn out satisfactoril)\ 



XVII. 

REGENERATION OF STEEL WHICH HAS BEEN 
SPOILED IN THE FIRE. 

When steel has been overheated to a high degree or 
roasted, it is best not to work it further for tools and spend 
money in their manufacture, since they will be brittle and 
crack, or do not acquire hardness. 

As a rule it is found out too late that the steel has been 
overheated or roasted, it being recognized only by the de- 
fects of the finished tool. Regeneration, i. e., an improve- 
ment of the spoiled steel, is then out of the question. In 
the manufacture of tools, nostrums for improving spoiled 
steel are of no appreciable value, the best means being to 
avoid mistakes. 

Steel is burnt when it has been heated to such a degree as 
to cause its structure to be dissevered, in consequence of 
which the steel in a hardened state shows edge cracks. In 
forging such steel it crumbles ; in hardening it cracks. It 
cannot be regenerated. 

Steel is overheated when it has been brought to above a 
bright-red heat, and in consequence of it acquires a coarse 
9 



130 TOOL-STEKL. 

•crystalline structure, whicli, according to the duration of 
overheating, is confined to the surface — edges and corners 
— or extends throughout the bulk of the steel. 

If in forging tool-steel has been partially overheated, and 
it is considered advisable not to remove the respective por- 
tion entirely, it is allowed to cool to a cherry-red heat, and 
then subjected to vigorous working, which is continued to a 
•dark-red heat. The tool having been allowed slowly to 
cool is then carefully reheated for subsequent hardening. 

Tools which have been overheated in hardening are 
allowed slowly to become cold, and are then carefully re- 
heated to the lowest hardening temperature permissible. 
By this process the fine structure is restored and the steel 
regenerated. All nostrums recommended for the regenera- 
tion of burnt or overheated steel have the same object in 
view, and by themselves are entirely without effect. Suc- 
cess in attempting to regenerate overheated steel is always 
doubtful. 

Tool steel is roasted or baked if, with the access of air, it 
has for some time been exposed to a temperature which by 
itself is not high enough to cause overheating. 

From the surface of such steel the content of carbon has 
been partially or entirely withdrawn. Tools manufactured 
from it do not acquire a sufficient degree of hardness, 
or remain entirely soft. If a tool is suspected of having 
been made of slightly roasted steel one of the previously 
described hardening agents, best in the form of a paste, 
may be used ; success depends on the degree of decarboni- 
zation, and is always doubtful. 

Steel is called dead when, while in use, it has been re- 
peatedly heated and hardened, and in consequence has 



DEFPXTS OF HARDKN'KD TOOLS. 131 

become brittle, has lost cutting power, and cracks readily in 
hardening. There are no other means of overcoming this 
than by removing the worn-out edge of the tool and re- 
newing it. 



XVIII. 

INVESTIGATION OF DEFECTS OF HARDENED 

TOOLS. 

If in inspecting hardened tools defects are found their 
causes should be immediately determined, so as to avoid 
them in subsequent operations. The art of hardening is a 
very difficult one, and requires great skill and long experi- 
ence if to be carried on with success. Such experience 
does not alone include a superficial knowledge of the hard- 
ening process to be employed in each case, but also an 
accurate perception of the causes of defects and the selection 
of the methods of working by which they may be avoided. 
The hardener of tools should from the start have a clear 
idea as to the process by which the object in view can be 
attained without probable failure, and should take measures 
that the various operations in hardening can be carried on 
without hindrance. 

When many tools of the same kind are to be hardened, 
the operation should commence with one piece, which im- 
mediately after hardening is cleaned under water by means 
of a sharp brush, and then examined as to cracks, and by 
means of a smooth file as to the degree of hardness. If no 
defect is discovered, a second piece may be taken in hand, 



132 TOOL-STEEL. 

the examination of which will show whether the hardening 
process adopted is a suitable one, and whether the opera- 
tion may be continued in rapid succession. Nevertheless it 
must not be omitted to subject the tools immediately after 
hardening to a cursory examination, and subject individual 
pieces to a searching inspection. 

With the use of too high a temperature, small tools 
hardened all over crack already during cooling ; this defect 
can at once be dealt with. 

The severance of corners and edges of larger tools also 
occurs mostly in the hardening bath, but at a later stage of 
cooling, so that the tools have to be allowed to rest for 
some time before the hardener can be assured that the 
work proceeds correctly and that hardening may be con- 
tinued ; otherwise it may happen that in the subsequent 
inspection all the hardened pieces may be found defective. 

Although too great an assurance in the correct selection 
of the hardening process, without scrupulous inspection 
frequently repeated, may lead to failure, uncertainty and 
timidity are just as objectionable. Precaution is then car- 
ried so far that larger tools are for hours roasted in the 
open fire to bring them to a quite uniform heat, and never- 
theless are finally hardened in an insufficient temperature. 
It may happen that this process is several times repeated, 
because in this way the tool does not acquire hardness, and 
the steel used is then blamed. Such uncertainty is charac- 
teristic of an inexperienced hardener. 

The following hints may serve as guides in the in- 
spection : 

1. Small tools, or tools of a small cross-section, which 
have been partially hardened, show cracks in the 



DEFECTS OF HARDENED TOOLS. 133 

centre running in the direction of the length in case 
they have been too highly heated, or if cracking has 
been due to flaws, contained in the steel before hard- 
ening. Break the thoroughly dried tool and com- 
pare the structure of the fractures with a sample 
of steel of the same cross-section and of the same 
quality, which has been carefully brought to a 
, cherry-red heat, hardened, and then broken. 

If the fracture of the tool shows a coarser struc- 
ture than the sample, hardening has been effected at 
too high a temperature. If the structure is fine and 
the sides of the crack are pure and only sprinkled 
with hardening water which has penetrated, failure 
may have been caused by the use of too cold water, 
or to a forging strain in the tool which has not been 
removed by annealing. By the use of warmer 
water or another hardening fluid (oil or tallow), or 
by carefully annealing the tool, this defect may 
readily be overcome. 

If the surfaces of the crack show a partially or 
entirely dark (brown-red) color, the failure is due to 
defective material, the dark coloration of the frac- 
ture being caused by oxidation of the steel in 
heating. 

2. Flat tools, such as knives, etc., or tooLs spreading out 

to a broad, sharp edge, such as chisels, drills, etc., 
show, after hardening, curved cracks on the corners 
and back of the edges. This is an indication of un- 
even heating or over-heating of the corners and 
edges. 

3. The corners, edges and teeth of larger tools which 



134 TOOL-STKEL. 

have been liardened in their entirety separate dur- 
ing or after hardening. If, witlj an otlierwise cor- 
rect hardening process, the fracture shows a coarse 
structure, partial over-heating is the cause of the 
failure, but if the fracture shows a fine structure, 
failure is due to incorrect cooling. 

4. Tools cracked from the interior have been incorrectly 

cooled if the surfaces of the crack when laid bare 
show a thoroughly coherent structure. If the fail- 
ure has been due to a pipe or other flaws in the in- 
terior of the steel, it may be recognized on the 
surfaces of the crack when laid bare. 

5. When cracks or separation of corners, etc., are 

noticed on one side of a symmetrical tool, it is indi- 
cative of uneven heating in hardening. 

6. Edge cracks running vertically to the edges and 

show^ing sides of a dark and black color occur only 
in burnt steel. 

If the structure of the steel is coarse and of a 
white glistening color, the tool has been burnt in 
hardening ; if the structure is coarse-grained but 
shows little lustre, the steel has been burnt in one 
of the operations previous to hardening. 

7. If hardened tools show an uneven degree of hardness, 

they have been unevenly heated for hardening, 
or unevenl}' cooled by not having been sufficiently 
moved about in the hardening fluid, or more cooled 
by it on one side. Tools which have been cooled 
only for a short time and then allowed to become 
cold while in contact with the walls of the cooling 
vessel, are apt to be soft on the places of contact. 



DEFECTS OF HARDENED TOOLS. 135 

8. When tools show a uniform degree of insufficient 

hardness it is more seldom due to too slight heating, 
but rather to an unsuitable hardening fluid, and 
perhaps also to too small a quantity of the latter. 

With the use of a lower hardening temperature 
and in hardening larger tools, cooling fluids acting 
with greater intensity should be employed, and water 
covered with oil, pure oil or fat should be avoided. 

9. Soft spots in hardened tools are formed when coal 

containing sulphur is used for heating. However, 
such spots are also formed when the hot tool is too 
slowly plunged in the cooling fluid, and the latter 
by being dashed upwards causes here and there soft 
spots. 

10. When the surface of a hardened tool is entirely cov- 

ered with a thin soft skin, which to a slight depth 
can readily be attacked with a file, the tool has been 
too slowly heated in hardening and superficially 
decarbonized. After removing the soft skin by 
grinding, the tool, as a rule, possesses a sufficient 
degree of hardness to permit its use, but its cutting 
power is of course considerably less than that of a 
well hardened tool. 

11. Tools which have been roasted or baked and much 

decarbonized in any of the operations previous to 
hardening, do not acquire any degree of hardness 
whatever. The fracture of the steel shows towards 
the edges dark streaks of dense lustreless structure. , 

12. The defects due to the tools which serve for handling 

the steel in hardening have already been discussed 
on p. 86. 



136 TOOL-STKKI.. 

In case tliero is a doubt or uncertainty about the pro- 
cesses of working to be employed as regards tlie quality 
and degree of hardness of the steel to be used or the pur- 
pose for which it is to be employed, it is advisable to apply 
for hardening directions to the source from which the steel 
has been obtained. 

By an immediate inspection of the hardened tool only 
part of the mistakes made in hardening or previous opera- 
tions can be found out. The defects noticed in using the 
tools are generally confined to a deficiency in the degree of 
hardness. Such defects are generally due to the fact that 
the degree of hardness has been incorrectly chosen, and 
partially to faulty hardening. If a tool is found to possess 
insufficient cutting power, it may be the fault of its not 
being hard enough as well as of its being too hard and 
brittle. Microscopical particles break out of the edges of 
tools which have become brittle in hardening and the 
edges soon become dull, the impression being the same as 
when too soft steel becomes rapidly dull. If it is attempted, 
as is frequently done, to remedy this defect by still more 
intense hardening, the result is the reverse. To give the 
tool better edge-holding power, it suffices, as a rule, to 
remove the superficial, more brittle, layer by grinding. 
When the edge has to be renewed a lower hardening tem- 
perature should be tried and less intense cooling. Should 
the efficiency of the tool remain unsatisfactory, it may be 
supposed that the degree of hardness selected has been too 
low. 

That with cutting tools of hard steel the highest attain- 
able degree of hardness does not always yield the greatest 
efficiency may be seen from the experiments made at 



DEFECTS OF HARDENED TOOLS. 



137 



Bismarckhuette, the results of which are given in the table 
below. 

For these experiments several cutters were made from 
one and the same bar of steel, and one-half of them were 
carefully hardened from a bright red heat in water of 
64.4° F., and without further tempering tested under the 
same conditions. The average efficiency of these was re- 
duced to the figure 100. The remaining half of the cutters 
were heated to not so bright a red heat, hardened in water 
of 64.4° F., until all heat had disappeared, plunged in boil- 
ing water and allowed to cool in it. 

The efficiency was better throughout, namely : 







Degree of hardness of tli 


e cutters. 




Intensely 
hardened 
in water. 


Hardened 
in water, 
tempered 
in boiling 
water. 


IS^n 


1. 

2. 

3. 
ing 


Steel with 0.85 % 
Steel with 1.32 9^ 
Special steel with 


carbon, 
carbon. 
1.57 % 


Efficiency • • 

Efficiency. 

carbon and 




o o o 
o o o 


112 


No. 

No. 


4.5 % 


118 
135 















The test was made upon annealed cast-steel of the same 
•degree of hardness as that of the cutters. 

It will be seen from the increase in efficiency, up to as 
much as 35 per cent., that by a suitable process of cooling 
an appreciable gain in time and efficiency can be attained. 
A defect frequently observed on very hard cutting tools 
consists in cracks w^hich are formed on the surface after 
previous grinding off of the worn-out edge and cause the 
uppermost layer of steel to peel off in the form of laminae. 



138 TOOL-STEEL. 

but which may also run in various diitctioiis throughout 
the entire tooL Dei'ective steel is, as a rule, blamed for 
these cracks, but this is generally a mistake, because they 
are formed by grinding upon hard, rapidly-revolving 
emery wheels, even if the latter run wet. 

These emery wheels attack the surface of the steel, and 
the area pressed against them being suddenly heated to a 
high temperature, a change in volume takes place, in con- 
sequence of which cracks are formed. With such emery 
wheels rapid cooling by the water is effected after the tool 
has been pressed against them, but remains ineffective dur- 
ing that operation. 

The above-described phenomenon is more frecjuently ob- 
served when dealing with hard cutting tools than with 
tools of a less degree of hardness. 

In using tools with engraved surfaces, for instance,^ 
stamping tools, which w'ork under high pressure, the sharp 
edges will frequently be observed to crumble. This is an 
indication of too high a degree of hardness, and can be 
remedied by laying for a short time a hot metal plate upon 
the tools before using them. 

The corners and edges of tools which, while in use, are 
exposed to a high degree of heating, readily become notched 
in the commencement of the operation. In consequence 
of heating, a superficial change in the volume of the steel 
takes place. The steel endeavors to contract, which is pre- 
vented by the layers underneath, which are still cold, the 
consequence being the formation of numerous fine cracks, 
and the tool becomes notched. To avoid this defect, the 
tool should be heated before use, and the more so the 
higher the degree of heating to which it is exposed during; 



DEFECTS OF HARDENED TOOLS. 139 

the work. Tools on which slighter demands are made are 
heated to hand-warm, and those exposed to a higher degree 
of heating are heated throughout to a uniform temperature 
in boiling water. 

The above-recommended process may be used to advant- 
age with dies and cutters, as well as with tools which while 
in use are heated by blow and shock. 

Incorrect, sharply-defined hardening causes the tool while 
in use to break off short, and this defect can then be readily 
noticed. 

The drawbacks due to too high a demand made on the 
tools or by too suddenly engaging them become manifest 
by the destruction of the tools themselves or of their edges, 
and the causes of this may be readily recognized and 
avoided. 

Without entering into a further explanation of the de- 
fects and blemishes which may originate in hardening, 
tempering and in using tools, it may be recommended to 
subject tools which appear faultless in hardening, but prove 
defective in use, to as careful an examination as if they had 
been found defective in hardening. Such examinations 
serve to increase the experience of the hardener. 



140 TOOL-STEEL. 

XIX. 

IMPROVJNG THE PKOPERTIES OF STRENGTH 
OF STEEL. 

The object of improving the properties of strength of 
steel is to give it special elasticity, strength, or toughness. 
In most cases the production of the greatest attainable 
strength and toughness is aimed at. 

As has been mentioned in a previous chapter, the co- 
hesive power of the structure of steel, which determines its 
strength and toughness, undergoes considerable changes in 
the operations of hardening, letting down, and by manipu- 
lation. By the operation of annealing the strength of steel 
is diminished and its toughness increased. By working 
steel at a low temperature its strength is increased, but its 
toughness decreased even to brittleness. 

Steel rolled or forged at a high temperature possesses less 
strength and greater toughness than steel worked at a low 
temperature. When it is of importance to give to steel for 
structural purposes uniform properties of strength through- 
out, it must be worked in a positively even temperature. 
Even properties of strength may be imparted to steel of 
varying quality by a suitable adaptation of the working 
temperature. 

By the operation of hardening, the strength of iron 
which is not capable of being hardened is essentially in- 
creased and its toughness reduced. Steel, which is capable 
of being hardened, loses in strength and all its toughness ; 
it becomes brittle. 

By the operation of tempering, the strength and tough- 
ness of steel are up to a certain limit increased. 



PROPERTIES OF STRENGTH OF STEEL. 141 

If letting-down is continued above the gray temper color 
up to the hardening temperature, the steel passes through 
the various stages of strength, the latter increasing to a 
certain tempering temperature, and then it gradually de- 
creases until it acquires the lowest degree, when a complete 
annealing temperature has been attained. The toughness 
of the steel increases thereby constantly. 

If steel is hardened and then heated to different temper- 
atures and allowed to cool, it will possess different degrees 
of strength and toughness. 

Similar phenomena may be observed on steel which has 
been cooled from the hardening temperature in fluids of 
different degrees of heat, for instance, in boiling water or 
in molten lead. 

The most useful methods for improving and regulating 
the properties of strength of steel by a suitable combination 
of hardening and reheating are patented, and are practically 
applied in the manufacture of steel weapons, for instance, 
cannon, and are still more widely employed in the manu- 
facture of machine parts on which great demands are 
made, railroad material, etc. 

For the application of this process the construction of 
suitable appliances is required, as well as extensive control 
of the properties of strength attained by means of machines 
serving for testing materials. 

For the manufacture of tools and their use, the methods 
for improving the properties of strength of steel are but of 
secondary importance ; they are unconsciously practiced 
by annealing, hardening and tempering the tool. 



APPENDIX. 



In works in which'^the manufacture of tools is carried on 
on a large scale, the output of large quantities of products 
of a similar nature comes, as a rule, only into question. 
The appliances which serve for the various operations in 
forging, hardening, tempering, etc., are established ; the 
methods of working are the result of experience and the 
necessity of avoiding every kind of loss, and, as a rule, 
have been properly selected. The same holds good as re- 
gards the skill and experience of the workmen who carry 
on the various operations in the manufacture of tools, and 
on whose attention, by reason of a suitable division of 
labor, but a limited demand is made. 

The toolsmith or locksmith is, however, confronted by 
entirely different conditions. Daily, nay hourly, demands 
are made on him in reference to the construction of tools, as 
is the case in establishments where many different kinds of 
tools are required for carrying on the work. 

In such establishments as, for instance, iron works, 
machine shops, etc., the rapid and uninterrupted progress 
of the various operations depends largely on tools of fault- 
less construction. Varied demands are made on the fore- 
man and workmen entrusted with this work, and to satisfy 
these demands, extensive knowledge and experience are 
required, as well as the necessary appliances. In practice 
such appliances are unfortunately seldom found, they being, 

( 142 ) 



APPENDIX. 143 

as a rule, so primitive as to prove rather a hindrance than 
an advantage in the manufacture of effective tools. 

The appliances for the different operations in the manu- 
facture of tools as far as they refer to the treatment of steel 
in heating and hardening have on the whole been described 
in the previous chapters. The process of working to be 
observed in these operations depends on the quality or hard- 
ness of the steel and the purpose for which the tool is to 
be used. 

Below, the mode of working to be observed in forging, 
annealing, hardening, and tempering a number of tools 
frequently called for will be explained. 

1. Hand Chisels. 

Quality of steel to be used : For locksmith's chisels for hard 
materials which are to hold their edges under light blows 
with the hammer, medium hard steel should be used ; for 
chisels to be worked by compressed air, hard steel. 

For chisels to be used upon soft materials under sharp 
blows of a heavy hammer, very tough steel should be 
used ; also for chisels with long and sharply stretched-out 
edges. 

Forging : At the utmost in a bright red heat. 

Hardening : Heating to a cherry-red heat, which should 
extend to about 0.59 to 0.78 inch back of the edge, and 
then backward in gradual transition. Plunging the edge 
about 0.78 to 1.18 inches inches deep in water of 64° to 
68° F., moving it about, then lightly up and down until 
all heat is quenched. 

For tempering the chisel is rubbed bright, the progress of 
the temper color followed up, and after the appearance of 



144 TOOL-STEEL. 

the violet or blue color it is fixed by plunging the chisel in 
water, which, if required, may be repeated, or in oil or soap 
water. 

Chisels which have to be very tough, are heated twice to 
the temper color, the first color being rubbed ofl' and heat- 
ing repeated. 

2. Hot and Cold Chisels. 

Quality of steel to he used : For hot chisels, medium hard ; 
for cold chisels, tough. 

Forging, hardening, and tempering, same as for hand 
chisels. 

If hot and cold chisels are to be subjected to particularly 
powerful blows, it is best to use a good quality of weldable 
steel to facilitate repairing of the heads, which are apt to 
fray and split, and to heat the edges only to a dark yellow 
or brown-red temper color. 

3. Rivet-Chisels. 
(For cutting off rivet heads.) 
These are treated in the same manner as hot or cold 
chisels. 

4. Center- Bits. 
Quality of steel : Medium hard to hard. 
Forging : Good cherry-red heat, if possible with the use 
of a charcoal fire. 

Hardening: After obtaining a uniform cherry-red heat, 
extending to about 0.39 inch back of the edge and then 
gradually decreasing, thinner bits are completely cooled in 
water and heated to a yellow temper color by heating the 
tools back of the edge. 



APPENDIX. 145 

Broad, thick bits are hardened in the same manner as 
hand chisels and tempered from the back end with the 
assistance of the fire if the heat stored in the tools is not 
sufficient for the purpose. 

5. Turning Knives and Planing Knives. 

Quality of steel : Hard to very hard. 

Forging: Cherry-red heat with the exclusive use of char- 
coal. By long continued forging, the steel readily breaks 
up, as well as by too powerful blows with the hammer. 
After forging, turning and planing knives should always 
be allowed to become cold. 

Hardening : Slow heating, with the use of little blast, to 
a scant cherry-red heat, extending to about 0.78 inch back 
of the edge and then gradually decreasing. Quenching in 
water by immersing to a depth of about 1.18 inches, and 
moving about, and up and down. When cool, rub off and 
heat to a full yellow temper color and finally cool slowly 
bj^ successive immersions for a short time in warm water. 

6. Roll-Turning Knives 
f^ of accompanying cross-section. 

Quality oj steel : Very hard, special steel. 

Forging : Grooved roll turning knives are cut off' from 
profile steel or shaped from the whole steel. 

Hardening : The highest attainable degree of glass hard- 
ness is demanded, which is not modified by letting-down. 

Heating for hardening should not be effected in the open 

fire but if possible in a muffle or a hardening furnace, and 

should at first be done slowly to a dark cherry-red, and 

then rapidly to not too bright a cherry-red, heat. When the 

10 



146 TOOL-STKEL. 

latter heat has been attained, the tool is quenched until 
entirely cold in pure water, or better in salt water or acidu- 
lated water. 

The cold knife is then laid in hot sand or hot water and 
allowed slowly to cool in it. With grooved turning knives 
hardened in their entirety, there is great danger of crack- 
ing, the latter occurring frequently, but there are no sure 
means of preventing it. 

7. Screw Taps. 

Quality of steel : For small taps, tough to tough hard ; for 
larger taps, tough hard to medium hard. 

Forging : Screw taps are turned and milled from the solid 
piece. 

Hardening : Taps worked singly are heated for hardening 
in an open charcoal fire by bringing the charcoal to a glow 
with the aid of considerable blast, then stopping the latter 
and bringing the tap to a dark cherry-red heat in the quiet 
fire thus obtained. Further heating to the hardening tem- 
perature is rapidly effected with the use of the blast. 

Taps almost cylindrical in shape are plunged vertically, 
twisted portions foremost, in water, and very tapering taps 
head foremost, the latter being allowed to cool throughout, 
while the former must be withdrawn far enough for the 
head to remain soft. When the heat is quenched the taps 
are withdrawn from the water — the latter still evaporating 
on the surfaces — then let down from the interior to from 
yellow to brown temper color, and finally cooled entirely. 

When a larger number of small taps are to be hardened 
at one time they are packed in a sheet-iron box between 
powdered charcoal and charred leather, and heated as pre- 



APPENDIX. 147 

YJously described. For hardening, the taps are singly taken 
Irom the box. 

In the open fire, large taps can only be brought to 
the hardening temperature after long-continued roasting, 
whereby superficial decarbonization frequently takes place 
and the teeth remain soft. To overcome this drawback 
they are heated for hardening in the hardening furnace, 
the teeth having been previously protected by hardening 
paste, or heating for hardening is effected in a muffle. 

If heating in an open fire cannot be avoided, packing in 
a sheet-iron box between charcoal and hoof meal should be 
resorted to. By letting down from the interior the teeth 
of large pieces would be struck too late by the advancing 
heat, and for this reason the tools should be cooled to as 
great a depth as possible, then allowed slowly to cool in hot 
sand or hot water, so as to avoid as much as possible a 
severance of teeth and corners. 

If letting down small taps during hardening is not desir- 
able, they are placed immediately after cooling in hot sand 
or hot water. Letting down is then eff'ected by heating 
the heads in a dim gas flame or spirit flame. 

8. Screw-dies. 

Quality of steel: : The same as for screw taps. 

Hardening : Heating for hardening is effected in the 
same manner as given for screw taps. Hardening and 
letting down are done as follows : 

The shape of screw-dies does not allow of letting down 
from the interior, and in hardening they must therefore be 
entirely cooled. To decrease the danger of cracking they 
should be cooled in a mild hardening agent — molten 



148 TOOL-STEKL. 

tallow — or in water until all heat has disappeared, and 
then allowed completely to cool in oil. 

Sharply hardened screw-dies are let down at a brown-red 
temper color, and screw-dies of a less degree of hardness at 
a yellow temper color, by laying them upon a weak char- 
coal fire, or better upon red-hot pieces of iron. 

9. Broaches. 
Quality of steel : Same as for screw taps. 
Hardening : Same as for screw taps. 

10. Spiral Drills for Metal. 

Quality of steel : Medium hard to hard. 

Hardening : Heating and hardening are effected in the 
same manner as with screw taps, but for the sake of uni- 
form heating, in the muffle, hardening furnace or in molten 
lead (salts). The difficulty of hardening the entire drill 
lies in the fact that it must not become much or at all 
distorted. 

In hardening from the open fire, if the use of the latter 
cannot be avoided, uneven heating is prevented by hard- 
ening the drill only ^ to J of its length if it is to be used 
for boring not very deep holes. Heating a shorter length 
results in an even hardening temperature, gradually de- 
creasing backward. 

Cooling is effected by plunging the drill vertically into 
a vessel of as great a depth as possible, moving it up and 
down with a rotatory motion. By moving it sideways it 
would readily become distorted in consequence of uneven 
lateral cooling. 

The drill when completely cooled is heated to a yellow 



APPENDIX. 



149 



Fig. 63. 




temper color, and while in this state is straightened in 
the screw press. 

Saturated solution of common salt, 
or of soda or sal ammoniac, is used as 
cooling fluid. 

Letting down is effected upon heated 
sand or over a charcoal tire in mod- 
erate glow, which can be readily pre- 
pared as shown in Fig. 63. 

11. Cannon Drills. 
Quality of steel, and hardening : Same as for spiral drills. 

12. Cutters. 

Quality of steel: For ordinary cutters for soft metals, 
tough hard to medium hard ; for cutters for hard metals 
on which great demands are made, medium hard to hard ; 
for cutters of complicated shape for wood on which but 
slight demands are made, tough to soft. 

Hardening : Slot and tenon cutters are hardened in the 
same manner as screw-taps and broaches. 

Small cutters are heated in the muffle built in the open 
fire, as shown in Fig. 3, or better in the hardening or 
muffle furnace. If several cutters are to be hardened at 
one time, they are packed, as described under screw-taps, in 
a sheet-iron box which is heated to the hardening tempera- 
ture. 

The cutters are cooled singly by plunging in water and 
moving them about in it ; they are then placed in hot sand 
and allowed completely to cool in it. 

Letting down is effected by placing them upon pieces of 



150 TOOL-STKEI,. 

red-hot iron of a slighter diameter, or by means of a red-hot 
mandril puslied through the hole. Temper color for the 
bore, violet ; for the teeth, brown-red. 

Large cutters of a fiat shape (l to about ^ of diameter to 
thickness) are hardened in the same manner but only 
heated — supported upon pieces of sheet-iron — in the hard- 
ening furnace, but better in the mufHe furnace. The teeth 
are protected by hardening paste, or with uneven heating, 
by scattering hardening powder upon them. 

If permitted by the shape of the cutters, pieces of sheet- 
iron should be used for protection. Letting down is 
effected in the same manner as with small cutters. 

The teeth of large or thick disc cutters, when continued 
on the sides, are very much exposed to being cast off in 
hardening if special care is not used in heating. Such 
cutters should not be cooled too long, but heated as soon as 
possible from the exterior by plunging them in hot water or 
covering with hot sand. Keheating to too high a degree is 
avoided by inspection, repeated shortly before cooling off. 

Large cutters, greater in thickness than diameter, are 
seldom made in one piece but divided as described on p. 78, 
Hardening of such cutters is beset with special difficulties, 
and should be effected as previously described. 

Profile cutters are mostly made with backward tapering 
teeth ; the cracking of long cutters in hardening is sought 
to be prevented by their suitable division. 

Profile cutters with teeth which, as shown in Fig. 64, 
form sharp corners towards the surfaces, are protected by 
pieces of sheet-iron, or, as shown in the same sketch, by 
continuing the teeth in a curve, if permitt-ed by the use for 
which the cutter is intended. 



APPENDIX. 



151 



In heating, the utmost attention has to be paid to the 
sharp corners, and they should be frequently cooled by 
scattering hardening powder upon them. 

Hollow cutting bodies are seldom used. They are hard- 
ened by means of a powerful jet of water, which is allowed 
to circulate in the hollow space. 

For cooling cutters, hardening water which has been 
repeatedly used should be selected, or solution of common 
salt, or of sal ammoniac. For larger or very complicated 

Fro. t)4. 





catters the hardening water is covered with a layer of oil. 
If, however the teeth on large cutters are of a small cross 
section or slight height, the use of a layer of oil should be 
avoided, otherwise the steel ma}^ readily remain soft. 

Cutters for wood are mostly profile cutters of complicated 
shape, which for this reason are difficult to harden if the 
tools are to possess a full degree of hardness modified by 
subsequent letting down. 

A higher degree of hardness and greater capacity of 
holding their edges than those of wood-working tools in 
general are seldom required for wood-cutters, and hence as 
a rule nothing more is necessar}- than good spring hardness. 

Wood-cutters are frequently made of very hard steel and 
successfull}' used in an unhardened state. However, on 
account of its being more easily worked, soft steel or steel 
of good hardening quality is selected. 



152 



TOOL-STEEL. 



If tough steel of good hardening quality is used, it is 
better to harden it in a mild cooling fluid and to use it 
without further letting down than to give a full degree of 
hardness and then letting down. 

Such cutters having been evenly heated to a cherry-red 
heat, are hardened in oil or in tallow and allowed to cool 
in it. 

The method of cooling wood cutters of harder steel in 
molten metals is less known. For this purpose molten lead 
(741.2° F.), tin (442.4° F.), zinc (772.0° F.), or a mixture 
of a known fusing temperature is used, for instance, 

Lead 8 parts. 

Tin 4 parts. 

which melts at 440° F. 

The cutters heated to a uniform bright cherry-red heat 
are plunged, as in ordinary hardening, in the molten metal 
allowed for a short time to remain in it, and then rapidly 
cooled in water. 

Cutters thus hardened possess a high degree of tough 
hardness, sufficient to give them the capacity of holding 
their edges in working wood. 

If a larger number of cutters are to be cooled at one time 
in molten metal, a constantly even temperature is abso- 
lutely necessary for uniform success, and hence a pyrometer 
should be used. 

13. Pipe-Cutters. 

Quality of steel: Tough hard to medium hard. 

Hardening : Inside cutters are hardened like broaches ; 
outside cutters are hardened under a descending water-jet 
which strikes the bore. 



appendix. 153 

14. Pipe-Cutting Knives. 
Quality of steel : Tough hard to tough. 
Hardening: After uniform heating to cherry-red, they 
are hardened in oil and used without further letting-down. 

15. Milling Tools. 

Quality of steel : Soft. 

Hardening : Small milling tools are hardened like hot 
and cold chisels ; large milling tools are hardened under a 
water jet conducted into the cavity. 

Letting down is effected in the same manner as with 
hand and hot and cold chisels, but may be entirely omitted 
if a suitable quality of steel has been used. 

16. Hammers. 
{Hand hammers, riveting hammers, sledge hammers, etc.) 

Quality of steel: As a rule, steel of a slighter degree of 
hardness is selected for these tools, which in hardening 
•does not require letting-down. 

Hardening: Long hammers, the faces of which can be 
heated separately without the heat reaching the face 
already hardened, are heated and hardened like hot and 
<3old chisels, each face by itself 

Short hammers which for the purpose of hardening have 
to be heated in their entirety, are first hardened on the 
narrow face by plunging them 1.18 to 1.57 inches deep in 
water, then withdrawing them somewhat for allowing the 
hardening to spread, and finally, entirely quenching them. 
The broad face retains sufficient heat to be hardened in a 
similar manner in an ascending water-jet, the narrow face 
being cooled by placing wet rags upon it. When the broad 



154 TOOL-STEKL. 

face is hardened under a descending water-jet, tlie Iiardt-ned 
narrow face is in tlie meanwhile plunticd in a vessel tilled 
with water. 

While hardening both faces, the center portion of the 
hammer has lost sufficient heat to allow of its being cooled 
by repeatedly plunging for a short time in water. 

17. Hammkr Swages. 

Quality of decl : Very tough to hard ; according to tlie 
purpose for which they are to be used, or to the demand 
made on them. 

Hardening : Swages with flat faces or elevations on them 
are, for hardening, heated in the open forge-fire so that the 
face to be hardened is heated last. The swage is placed in 
the fire, the latter having been brought to a uniform, ex- 
tensive glow by putting on a large quantity of fuel and 
with the use of the blast. The swage with the foot towards 
the blast is brought into the fire and allowed slowly to 
heat, the blast having been shut otf enough to just main- 
tain the glow. 

When the entire tool has thus been brought to a uniform 
dark cherry-red heat, it is turned and the face is rapidly 
heated to the hardening temperature, care being taken not 
to overheat the corners of the swage, otherwise they may 
readily break off in the subsequent hardening. 

During heating the scale formed on the face is scraped 
off" and hardening powder preventing oxidation scattered 
upon it. 

The sufficiently heated tool is then hardened by placing 
it, face down, upon supports in a vessel into which the 
water enters in a powerful ascending jet. (See Figs. 48 
and 51.) 



APPENDIX. 155 

The swage is plunged 1.18 to 1.57 inches deep in water 
until the portion projecting from the water shows only a 
brown-red. It is then withdrawn to from 0.59 to 0.78 inch 
for the purpose of obtaining a gradual transition of the 
hardness, and then allowed to cool completely. 

This process is subject to a modification if the swage has 
been made of hard, instead of mild, steel. Hardening 
is then interrupted after the face has been cooled, the swage 
is lifted from the water, and after rubbing its surface bright, 
is let down from the interior to a yellow to brown-red 
temper color ; it is then further cooled in the above- 
described manner. 

When the face of the swage is deeply engraved it cannot 
be hardened in ascending water, otherwise the depressions 
may readily remain soft. Hence, it is hardened under an 
ascending water jet which is uniformly distributed over the 
entire surface by a rose of suitable form and size, a rose fed 
by two supply i)ipes being to advantage used for the pur- 
pose. The water must, of course, enter under powerful 
pressure. When hardening has sufficiently progressed to 
allow of letting down, the supply of water is shut off, and 
after the face has been brought to the temper color, cooling 
is continued until the tool is cold. 

For rapidly running hammers working with a weak 
blow, and for swages with very narrow faces, hard steel 
may be used. For swages with broad faces, especially 
when subject to vigorous blows, steel as tough as possible 
should be employed. Swages of hard steel are more subject 
to cracking in hardening, and also crack frequently while 
in use. 

Defects are also frequently due to bad usage, if the 



156 TOOL-STEEL. 

swages have been incorrectly set so that they obliquely 
strike one upon the other, or when thoroughly heating 
them throughout every time before use has been neglected. 
If shortly after beginning work the surfaces of the swages 
show fine cracks running vertically to the edges, or criss- 
cross cracks, it is generally due to the fact of them not 
having been hardened to a sufficient depth. The steel 
under the hard surface is soon upset, and as the harder sur- 
face cannot follow the change in form, it cracks in different 
directions. 

18. Round and Circular Shear-Knives. 
(Roll Shear-knives.) 

Quality of steel : Tough. 

Hardening: For hardening such shear-knives are heated 
exactly in the same manner as disc cutters. Cooling in the 
hardening fluid is effected until the knives are entirely 
cold, and the hardened knives are then placed in hot water 
or in hot sand. In letting down care must be taken that 
the cutting edges acquire a very uniform brown-red temper 
color. 

19. Shear-Knives. 

Quality of steel : Tough steel is used for long knives, 
which are principally to be used for cutting sheet metal, 
and for short knives for cutting iron and steel, on which 
great demands are nrade. Small shear-knives for actual 
cutting are made of tough hard to hard steel. 

Warm shear-knives are mostly used in the unhardened 
state. 

Hardening : Small shear-knives are best heated for this 
purpose in the hardening or muffle furnace. When heat- 



APPENDIX. 157 

ing in an open fire one with two or three tuyeres should be 
used, with charcoal as fuel. 

Narrow knives are gradually brought to a throughout 
uniform cherry-red heat, care being taken not to overheat 
the corners, which otherwise in hardening break off in a 
curved crack. 

Hardening is effected by vertically plunging in water. 
With the use of hard qualities of steel, holes, slots, screw- 
holes, etc., are filled with dry clay ; with the use of tough 
steel this is not necessary. 

Broad, short knives are heated on the edges to a uni- 
form cherry-red heat, gradually decreasing backward. 
They are then hardened by slowly plunging them, edges 
foremost, in water, and allowed to cool until the interior 
heat suffices for the production of the purple-red to violet 
temper color, when they are allowed completely to cool in 
water. Such knives of very tough steel can, after thus 
being partiall}^ hardened, be used without letting down. 

These knives may also be hardened by heating them in 
their entirety and cooling. Letting down is then effected 
by heating the backs in sand, lead, or in a quiet char- 
coal fire. 

Great difficulties are met with in heating long shear- 
knives, because heating has to be very uniform in order to 
prevent distortion in hardening. Heating in the open fire 
is most difficult of all. For this purpose fires with several 
tuyeres, one alongside the other, are required, as well as 
the erection of a structure as shown in Fig. 3, so that the 
heat may be kept better together. Hence heating is 
effected to better advantage in a charcoal furnace of simple 
construction, such as shown in Fig. 8, in which a heat 



158 



TOOL-STEEL. 



uniformly extending over the entire knife cun readily be 
obtained. 

It has to be borne in mind that the knives must first be 
heated from the back, and finally on the edges, so that the 
latter show the highest temperature before cooling. 

For hardening the knives are caught on the ends and 
plunged backs foremost in the water and unifonnl}' cooled. 

Letting down is effected in the most simple manner, in 
molten lead, the knives being immersed backs foremost, or 
in hot sand. When neither molten lead nor hot sand is 
available, recourse may be had to the following device : 

Set two rows of bricks, about 5| inches apart, upon the 
ground, form a grate by placing iron rods across them, and 
set two more rows of bricks upon the grate. The structure 
should be somewhat longer than the knives, and is closed 
at the ends by bricks. The device is shown in Fig. 65. 

Charcoal brought to a uniform glow in an open fire is 



Fig. 65. 



Tn"ii3j J ill iinr 




put upon the grate, and the knives are placed singly, one 
after the other, backs foremost, in the charcoal. 

Slight differences in temperature are equalized by push- 
ing the knives back and forward during heating, and un- 
even letting down is prevented by cooling places which are 
too highly heated by means of wet rags. 



appendix. 159 

20. Machine Knives for Cutting Paper, Knives for 

Splitting Leather, Planing and Cutting 

Knives for Wood. 

Quality oj steel : Tough to medium hard. 

Hardening : The operations for hardening, heating and 
letting down are the same as for hardening shear-knives. 

Great care must be observed in heating to prevent the 
sharp edges from becoming overheated, and heating must 
be very uniform to avoid distortion in hardening. These 
knives are at the best difficult to harden. They are 
straightened during letting down at the highest tempering 
temperature. 

While these knives must not be too hard, but should 
possess great power of keeping their edges for a long time 
when used upon soft materials, it is preferable to harden 
them in tallow or train oil, the danger of warping or crack- 
ing being thereby considerably reduced. 

21. Stamping Knives 

for stamping out of leather (soles and heels), paper, 
paste-board, bristol-board, etc. 

Quality of steel : A good quality of weldable cast steel or 
weld-steel. 

Hardening : For this purpose the knives are best brought 
in the muffle to a good cherry-red heat, the edges being 
previously protected with a hardening paste, and when a 
uniform hardening temperature has been attained, they are 
cooled, backs foremost, in oil or tallow. 

Letting down to a yellow or violet temper color is effected 
by placing the knives upon their backs in hot sand, lead, 
or upon red-hot iron plates. 



160 TOOL-STEKL. 

22. CiRCULAli KNIVKh;. 

(Simple, straight and plate knives.) 

Quality of steel: Tough to tough hard. 

Hardening: Small circular knives are brought in the 
muffle to a uniform cherry-red heat and hardened in 
tallow. 

Letting down is effected in the same manner as with 
round shear-knives. Circular knives of large diameter are 
brought for the purpose of hardening to a uniform cherry- 
red heat, care being taken to get the heat, if possible, last 
on the curved edges of plate knives, and to see that the 
heat is as uniform as possible, otherwise distortion is un- 
avoidable. 

For hardening, use a narrow long vessel with holes in 
the sides for fixing a crank shaft u})on which the knife to 
be hardered is stuck. The knife should dip in the cooling- 
fluid as far as it is to be cooled, and is then hardened by 
rapidly revolving it. To attain a uniform transition from 
the hardened edge towards the centre, water covered to a 
suitable depth with oil is used as cooling fluid. 

23. Punches and Dies. 

Quality of steel: For the punches somewhat harder steel, 
namely, tough hard to medium hard, than for the dies is 
used : for the latter, tough hard to tough. 

Forging and annealing : In forging punches and dies and 
stamps, overheating of the working edges and corners must 
be carefully guarded against, it being especially injurious. 
The object of annealing is to facilitate the working of the 
steel, but to avoid partial decarbonization of the surfaces 
and edges these tools should be annealed packed in a box 
between powdered charcoal or hoof meal. 



APPENDIX, 161 

Hardening : In hardening the punches it must be borne- 
in mind that they are ahnost exclusively engaged on the 
edges and must be capable of holding them for a long 
time. Hence, for hardening the}^ are first heated from the 
rear, and as soon as the upper portions show a uniform 
dark cherry-red heat, the front portions are brought to 
the hardening temperature. 

Hardening is effected in the same manner as with turn- 
ing knives by cooling to a certain depth — as far as the 
punch is to be hard — and letting down from the rear of the 
red-hot tool to dark yellow to violet temper color. More 
seldom the entire punch is cooled off", and letting down 
effected by reheating the back portion. 

The dies are mostly made of mild steel and of but a 
slight height. Low dies are heated for hardening to a uni- 
form cherry-red heat, it being advisable to protect the in- 
ternal cutting edges from decarbonization by coating them 
with hardening paste, or from overheating, by scattering 
hardening powder upon them. The die is then hardened 
in its entiret)'^ by plunging it vertically in the hardening 
fluid. 

When made of very mild steel the die is used with its 
full hardness, but when made of harder steel it has to be 
let down, which is effected by placing it upon a red-hot 
iron plate until the yellow temper color appears upon the 
surface. 

High dies are not hardened in their entirety, but by a 
descending water-jet which must strike with particular 
force the surfaces and interior openings. The process is 
the same as for swages. 

Crumbling of the edges of dies in use, which is frequently 
11 



162 TOOL-STKEI,. 

observed, is due to too liigh a degree of hardness; the for- 
mation of fine cracks is caused by the hardness not pene- 
trating to a sufficient depth. 

24. Stamps and Dies. 

These differ from punches and dies in that they have 
not a cutting effect, but transfer by pressure a more or less 
shar]) engraving to metals laid between them. 

Qualify of steel : Medium to very hard, special qualities 
being particularly serviceable for this purpose. 

Hardening : The duty demanded from the stamp and the 
die being the same, they are made of steel of the same de- 
gree of hardness. Both are also hardened in the same 
manner. 

In heating stamps and dies care must be taken that the 
engraved surfaces do not become decarbonized or covered 
with scale. However, since these pieces have mostly large 
cross-sections and must be hardened in their entirety, they 
have to be heated for some time and there is always danger 
of decarbonization as well as of the formation of scale. 
This is prevented by heating the tools packed in a box 
between horn and hoof shavings. With long-continued 
heating the cementing action of charcoal or charred leather 
is too great, and the use of these agents should, therefore, 
be avoided. 

The hardening process itself has been described on p. 76. 

25. Punches and Dies for Perforating Holes in 

Metals. 
Quality of steel : For dies, mild, tough to tough hard steel. 
For punches to be used upon thin metals, tough hard to 



ATPENDIX. 163 

medium hard steel ; for punches for thick articles of hard 
metals, medium hard to hard steel, and special qualities 
serving for this purpose. Generally speaking, what has 
been said in reference to forging and hardening of punches 
and dies, also applies to these tools. It is, however, neces- 
sary to say something in reference to the treatment of 
punches on which great demands are made, for instance, 
in the preparation of railroad material in punching fish- 
plates, bed-plates, etc. 

Instead of forging the working part of the punch, it is 
better to turn it and give it its final shape by filing. In 
forging, the portion of the punch on which the greatest 
demands are made, is readily overheated, and in upsetting, 
as is mostly done for the purpose of obtaining a broader 
surface of application, the cohesive power of the structure 
is injured, which, when the tool is used, results in the steel 
peeling off concentrically. For hardening, the punch is 
heated in an open fire with the exclusive use of charcoal, 
or better in a muffle. The thicker portion is first heated 
and brought to a cherry-red heat, and then the portion on 
which the greatest demand is made. Overheating of the 
edges and corners must be carefully avoided, and should 
they become heated too early or too highly, they are cooled 
by dabbing with wet rags, or by scattering hardening 
powder upon them. 

For the purpose of hardening, the punch is plunged 
vertically in the hardening water so that the thick portion 
is also cooled to a depth of from 1.18 to 1.57 inches, the 
punch being moved about until cooled off. It is then 
withdrawn and allowed to blue from the thick portion. 
The blue temper color is chosen, and when the punch has 



164 TOOL-STEEL. 

been somewhat highly heated, hence has been quite sharply 
hardened, it is twice blued. A fine smooth file should just 
take hold on the tempered surface. If not cooled at all, or 
only in water, such punches become quite .hot when used, 
and become covered with a firmly adhering layer of the 
metal which is punched. Hence cooling is effected by 
means of oil. 

Before use the punches are heated throughout in a quiet 
coal fire so that they can just be touched with the hand, 
or, what is still better, they are placed for some time in 
hot, or for a shorter time in boiling, water. 

26. Mandrils 
for drawing metal cases and tubes. 

Quality of steel : Tough hard to tough. 

Hardening : Uniform heating is readily attained only in 
the muffle. Hardening from melted salts is especially 
recommended (see p. 98). 

Hardening is effected by plunging the mandril vertically 
in water, to which a quantit}^ of common salt may advan- 
tageously be added. 

Tempering is effected by heating the head of the tool in 
a gas flame, alcohol flame, or by immersion in hot lead. 

27. Draw Plates. 

Quality of steel : Hard. 

Harde7iing : For hardening the plates are heated in their 
entirety, and the inner surfaces, which are engaged in use, 
are protected from decarbonization by the use of hardening 
paste and hardening powder. 

Narrow draw plates are hardened in their entirety by 



APPENDIX. 165 

cooling off in water ; broad draw plates with narrow holes, 
by conducting a powerful water jet through the interior. 

28. Pillow-blocks and Pivots. 

Quality of steel : Medium hard to hard. 

Hardening : When large, the engaged surfaces of pivots 
are hardened under a falling water jet, and tempered to the 
pale yellow to straw-yellow temper color. 

Pillow-blocks are hardened in their entirety by cooling 
them, apertures down, in a powerful ascending water jet. 
If the apertures are deep, cooling is effected under a power- 
ful falling water jet. Subsequent letting down is effected 
over a faintly glowing charcoal fire, in hot sand or upon a 
red-hot iron plate. 

29. Stone-Working Tools. 

The selection of the quality of steel for these tools de- 
pends not only on the kind of tool but also on the hardness 
of the stone to be worked. 

There is a large variety of these tools, but their construc- 
tion is, as a rule, ver}^ simple, and the operations in hard- 
ening and tempering are readily carried out and require 
but little attention. 

Since nearly all stone-working tools are subject to blow 
and shock and are seldom hardened in their entirety, the 
directions given for hardening hand chisels, hot and cold 
chisels, and hammers also apply to them. 

When hard steel is used, the treatment must of course be 
very careful and overheating be avoided. 

30. Tools for the Manufacture of Nails. 
Tools serving for the manufacture of nails are subject to 



lOG TOOL-STKKL. 

various demands wliich have to be satisfied by selecting 
the suitable quality of steel and using an appropriate 
metliod of hardening. 

The appliances for the operations of hardening and tem- 
pering should be selected with the greatest care, since the 
efficiency of the machine is dependent on the quaHty of the 
tool used and uniformly good efficiency can only be at- 
tained by uniformly good hardening. 

The varied demands made on these tools and the differ- 
ent purposes for which they are used, do not allow of de- 
tailed directions to be given for hardening them, and the 
reader is therefore referred to the hardening methods and 
the appliances required, which have previously been de- 
scribed. 

31. Balls. 

Quality of deel : Medium hard to hard. 

Hardening: In hardening balls which chiefly serve for 
bearings in rapid-running machines, it should be borne in 
mind that they must possess surfaces as pure and glass- 
hard as possible. 

Small balls are heated, in large numbers at one time, in 
the muffle and allowed to drop into a deep vessel filled with 
water. Hardening is thus readily and completely effected 
without fear of the balls cracking. 

On the other hand, in hardening large balls many diffi- 
culties are encountered as regards cooling off and cracking, 
since the strains operating from all sides towards one point 
may not only cause lamellar peeling off of the hard sur- 
faces, but also cracking from the interior. 

Since large balls Avhen simpl}^ plunged in the hardening 
fluid do not lose, in sinking down in it, their heat with 



APPENDIX. 



167 



sufficient rapidity and acquire an uneven degree of hard- 
ness in contact with the walls of the vessel, it is necessary, 
during cooling, to keep the hardening Huid in motion. 

By handling the ball with ordinary tongs the surface of 
the ball would readily receive impressions and the places 
caught by the tongs acquire an uneven degree of hardness. 

Fig. 66. 




Hence tongs are used, the jaws of which are made of very 
thin iron in the shape of a basket, Fig. 66, by means of 
which the heated ball can be handled without pressure and 
in hardening be brought on all sides in contact with the 
cooling fluid. 

Fig. 67. 




Waferpipei, 



Uniform cooling may also be effected by means of the 
device shown in Fig. 67. 

Fit a vessel, about 3.9 inches above the actual bottom, 
with a sieve-bottom of the shape shown in the illustration. 
Four or more pipes conveying in a slanting direction water 



168 TOOL-STEEL. 

under great pressure, enter the vessel 0.39 to 0.78 inch 
above the sieve-bottom. The upper edge of tlic hardening 
vessel is provided with a notch to allow the water to run 
off; and the water supply is so arranged that it can be 
shut off. Before commencing hardening the supply pipe is 
opened and tlie ball is thrown into the strongly agitated 
water, in which it sinks to the bottom and is kept in con- 
stant motion by the water flowing in. 

If the hardened balls were allowed completely to cool ofif 
in the hardening bath, much waste would result from 
cracking. Therefore, to equalize the temperature and 
hardening strains, they are brought before they are entirely 
cooled inside into hot sand, an open fire, or hot water. It 
is absolutely necessary for forged balls (in contradistinction 
to balls turned from the solid steel) to be annealed previous 
to hardening in order to remove the forging strains which 
are formed b}^ upsetting the corners and edges of the ball- 
form obtained from a cylinder or cube. Annealing is 
effected by one of the methods described on p. 48. 

32. Rolls. 

Rolls have to be made of very hard steel, since their sur- 
faces must possess a uniform glass hardness, and hardening 
them is one of the most difficult problems confronting the 
hardener. 

The process of hardening a large roll is described by the 
following example : 

The danger of cracking from the interior has been re- 
duced in the construction of the roll by boring it out. The 
entire surface of tlie roll, a-a, h-b, Fig. 08, is to be hard, 
while the journals, z-z, are to remain as soft and tough as 
possible. 



APPENDIX. 



169 



Previous to heating, the journals, z-z, are given a coat of 
loam or clay, which, to make it more binding, is mixed 
with cows' hair and, to prevent peeling off in consequence 
of shrinkage by heating, with chamotte, graphite, pulver- 
ized fire-brick, etc. Each journal is enclosed in a sheet-iron 
pipe of as large a diameter as the thickest part of the roll, 
and the mixture rammed in between the pipe and the 
journal. At m-m discs of sheet-iron projecting beyond the 
«dge of the roll are arranged. Finally the bore, the ends 







of which are provided with screw threads, are up to the 
latter rammed full of dry loam. 

In heating the i-oll, which frequently requires several 
hours, it must be borne in mind that during this time the 
surface is exposed to the injurious effect of the gases of 
combustion, as well as to decarbonization, if suitable pro- 
tection is not provided. For this purpose the roll is 
enclosed in a sheet-iron pipe of somewhat larger diameter, 
and after the space between the roll and the pipe has been 
rammed full of hoof shavings or soot the edges of the pipe 
are turned in. 

The roll may now be brought into the least heated part 
of a reverberatory furnace of sufficient width and allowed 
•slowly to heat. Heating in a reverberatory furnace is pre- 



170 



TOOL-STEKJ,. 



ferable, because other a})pliaiu'es, for iiistanco, lieating with 
charcoal, are not always available, if the roll has to be turned 
to attain a uniform temperature. The reverberatory fur- 
nace used should have as long a hearth as possiVjle, so as to 
cause a heat graduall}' increasing towards the fire-place. 

Fig. ()H. 





The roll is now gradually rolled into the higher heat 
and turned, the more frequently the hotter it becomes. 
When the roll is supposed to have acquired the suitable 
hardening temperature, a hook is screwed in the threads on 
the end of the journal and the roll is suspended by it by 
means of a chain. It is then freed from the sheet iron 
discs which can be readily removed, and quickly cleansed 
from adhering hoof shavings with a wire brush. The roll 



APPENDIX. 171 

is then plunged in the hardening bath, which should be 
located near the furnace. 

Since uniform cooling off of a roll of large diameter by 
moving it about in water is impossible, it is allowed to rest 
whilst the water is brought into vigorous motion. 

This object is attained by the appliance shown in Fig. 
69. It consists of a vessel of sufficient depth and of a 
diameter twice to four times as large as that of the roll,^ 
and is provided with pipe conduits for the introduction in 
a slanting direction of water under pressure. 

The mouths of the pipes are made broad and slit-shaped^ 
and a number of them are distributed at various heights so 
that the water around the roll is set in a vigorously whirl- 
ing motion. The manner of using this appliance will be 
readily understood from Fig. 69. 

The roll is for several hours cooled with the water flow- 
ing in, and then for some time in quiet water. 



172 TOOL-STEEL. 

Table for the Conversion op Centimeter* to Inches. 



Centi- 


British 


Centi- 


British 


Centi- 


Britisii 


Centi- 


British 


meters. 


Inches. 

0.394 


meters. 
51 


Inches. 


meters. 
101 


Inches. 
39.764 


meters. 
151 


Inches. 


1 


20.079 


59.450 


2 


0.787 


52 


20.473 


102 


40.158 


152 


' 59.844 


3 


1.181 


53 


20.866 


lOH 


40.552 


153 


60.237 


4 


1.575 


54 


21.260 


104 


40.946 


154 


60.631 


5 


1.968 


55 


21.654 


105 


41.339 


155 


61.025 


6 


2.362 


56 


22.048 


106 


41.733 


156 


61.418 


7 


2.756 


57 


22.441 


107 


42.127 


157 


61.812 


8 


3.150 


58 


22.835 


108 


42.520 


158 


62.206 


9 


3.543 


59 


23.229 


109 


42 914 


159 


62.600 


10 


3.937 


60 


23.622 


110 


43.307 


160 


62.993 


11 


4.331 


61 


24.016 


111 


43.702 


161 


63.387 


12 


4.724 


62 


24.410 


112 


44.095 


162 


63.781 


13 


5.118 


63 


24.804 


113 


44.489 


163 


64.174 


14 


5.512 


64 


25.197 


114 


44 883 


164 


64.568 


15 


5.906 


65 


25.591 


115 


45.276 


165 


64.962 


16 


6.299 


66 


25.985 


116 


45.670 


1 (^0, 


65.355 


17 


6.693 


67 


26.378 


117 


46.064 


167 


65.749 


18 


7.087 


68 


26.772 


118 


46.4.57 


168 


66.143 


19 


7.480 


69 


27.166 


119 


46.851 


169 


66.537 


20 


7.874 


70 


27.599 


120 


47.245 


170 


66.930 


21 


8.268 


71 


27.953 


121 


47.639 


171 


67.324 


22 


8.662 


72 


28.347 


122 


48.032 


172 


67.718 


23 


9.055 


73 


28.741 


123 


48.426 


173 


68.111 


24 


9.449 


74 


29.134 


124 


48.820 


174 


68.505 


25 


9.843 


75 


29.528 


125 


49.213 


175 


68.899 


26 


10.236 


76 


29.922 


126 


49.607 


176 


69.293 


27 


10.6.S0 


77 


30.315 


127 


50.001 


177 


69.686 


28 


11.024 


78 


30.709 


128 


50.395 


178 


70.080 


29 


11.417 


79 


31.103 


129 


50.788 


179 


70.474 


30 


11.811 


80 


31.497 


130 


51.182 


180 


70.867 


31 


12.205 


81 


31.890 


131 


51.576 


181 


71.261 


32 


12.599 


82 


32.284 


132 


51.969 


182 


71.655 


33 


12.992 


83 


32.678 


133 


52.363 


183 


72.048 


34 


13.386 


84 


33.071 


134 


52.757 


184 


72.442 


35 


13.780 


85 


33.465 


135 


53.151 


185 


72.836 


36 


14.173 


86 


33.859 


136 


53.544 


186 


73.230 


37 


14.567 


87 


34.252 


137 


53.938 


187 


73.623 


38 


14.961 


88 


34.646 


138 


54.332 


188 


74.017 


39 


15.355 


89 


35 040 


139 


54.725 


189 


74 411 


40 


15.748 


90 


35.434 


140 


55.119 


190 


74.804 


41 


16.142. 


91 


35.827 


141 


55.513 


191 


75.198 


42 


16.536 


92 


36.221 


142 


55.906 


192 


75.592 


43 


16.929 


93 


36.615 


143 


56.300 


193 


75.986 


44 


17.3.3 


94 


37.008 


144 


56.694 


194 


76.379 


45 


17.717 


95 


37.402 


145 


57.088 


195 


76.773 


46 


18.110 


96 


37.796 


146 


57.481 


196 


77.167 


47 


18.504 


97 


38.190 


147 


57.875 


197 


77.560 


48 


18.898 


98 


38.583 


148 


58.269 


198 


77.954 


49 


19.292 


99 


38.977 


149 


58.662 


199 


78.348 


50 


19.685 


100 


39.371 


150 


59.056 


200 


78.742 



INDEX. 



A CIDS, 99, 100 



Alcohol, effect of, on water, 100 
Aluminium steel, 1 
Animal substances for case-hardening, 

121 
Annealing boxes, 50 

furnace for forged pieces, 50-52 

long articles, 55 
general rule applying to, 49 
operation, controlling the result 

of tlie, 54, 55 
pots, furnace with, 53 
practical execution of, 50 
protection of steel from the air in, 

49, 50 
steel, appliances for, 48-55 

in annealing pots or in anneal- 
ing boxes, furnace for, 52 
Anvil, straightening, 118 
Armor-plates, mode of giving a hard 

surface to, 127 
Arsenic, 4 
Atlas steel, 1 

BALLS, hardening and tempering 
of, 166-168 
Bearings, balls for, hardening and 

tempering of, 166-168 
Bessemer steel, 1 
Bicycles, parts of, annealing furnace 

for, 50-52 
Bisniarckhuette, classification of steel 
in, 12 
experiments regarding the effi- 
ciency of tools at, 136, 137 
investigations in, 5 
Blast, action of, upon steel, 31, 32 
for open fires, 27 
weakening the effect of, 32 
Blisters, 18 
Boreas steel, 1, 12 
Bristol-board, knives for stamping out, 

hardening and tempering of, 159 
Broach of large cross-section, bored 

out, 79 
Broaches, hardening of, 148 
Burning in, 122, 123 



CANNON drills, hardening and tem- 
pering of, 149 
Carbide, 4 

Carbon, etl'ect of absorption of, by iron, 
119 
heating with, on iron 
or steel, 119 
graphitic, 4 
hardening, 3, 4 
occurrence of, in iron, 3, 4 
Carburetted hydrogen, 127 
Case-hardening and preventatives 
against superficial decarboniza- 
tion and overheating, 119-127 
application of, in practice, 120 
carbonaceous substances employed 

in, 120,, 121 
operation of, 120 
Cast steel, 2 
Centimeters to inches, table for the 

conversion of, 172 
Centrebits, forging, hardening and 

tempering of, 144, 145 
Charcoal for case-hardening, 121 
fui-nace to be operated with, 38 
muffle furnace for, 42, 43 
Chisel steel, 1 

Chisels, hand, forging, hardening and 
tempering of, 143, 144 
hot and cold, forging, hardening 

and tempering of, 144 
rivet, forging, hardening and tem- 
pering of, 144 
Chrome steel, 1 
Chromium, 7, 8 

Circular knives, hardening and tem- 
pering of, 160 
Clay, cooling with, 104 
Coal, furnace for, 40, 41 

smith or forge, 25, 26 
Coke-dust, 26 

furnace to be operated with, 35-38 
hard. 24, 25 

furnace for, 40, 41 
mild, soft. 30 
Common salt, 99 
Cooling agents, gaseous, 104 



(173) 



174 



INDEX. 



'Cooling agents, solid hodies as, 104, 
105 
balls, device for, 1(57, 168 
increase in the efficiency of tools 

by a suitable process of, I'M 
powder, 125 
rolls, appliance for, 171 
tools, general rule for, 83 

in hardening and devices for 
this purpose, 83-96 
Copper, 4 

Cracking from the interior, 73, 74 
on or near tlie surface, 74, 75 
prevention of, 70 
Cracks. 16 

force of strain in forming, 70 
formed by uneven cooling, 85 
progression of, 107 
■Crucible, cast iron, for melting metals 
or salts, 68 
steel, silicon in, 5 
steel, 1, 2 
•Cutters, annealing furnace for, 50-52 
broad, protecting the sharp cor- 
ners of, 81,82 
hardening and tempering of, 149- 
152 
•Cutting knives for wood, hardening 
and tempering of, 159 

DEFECTS of hardened tools, in- 
vestigation of, 131-139 
Diamond steel, 1 

Dies and punches, for perforating 
holes in metals, hard- 
ening and tempering 
of. 162-164 
hardening and tempering 
of, 160-1()2 
stamps, hardening and tem- 
pering of, 162 
Draw-plates, hardening of, 65, 66 

and tempering of, 
164. 165 
Drills, cannon, hardening and tem- 
pering of, Hit 
spiral, for metal, hardening and 
tempering of, 148, 149 

EDGE cracks, 17 
Emerv wheels, cracks caused by, 
137, 138 



Fire, open, protection of steel from the 
blast in an, 32 
tempering in an, 112 
zones of heat in an, 27 
-treatment of steel, practice of the, 
22-48 
Flaws, 18 
Forge coal, 25, 26 
Forging, changes in shape by, 20 

reverberatory furnace, ordinary, 

44, 45 
.strains, i9 
Fracture, manner of eHecting, 21 

of steel, appearance of, 17-19 
Fuel, charcoal as, .30, 31 
Furnace, annealing, for forged pieces, 
50-52 
long articles, 55 
for coal, 40, 41 

hard coke, 24, 25, 40, 41 
annealing steel in an annealing 
pot or in annealing boxes, 52 
heating long articles, 39, 40 
tempering by means of hot 
sand, 113 
forging and hardening reverbera- 
tory, 46 
most simple type of, 35 
ordinary forging reverberatory, 

44, 45 
provisional, conversion of an open 

fire into a, 28, 29 
reverberatory, small, 45 

with Gasteiger's patented fire- 
place, 47, 48 
muffle, 48 
small reverberatory, with step 

grate, 47 
to be operated with charcoal, 38 

coke, 35-38 
with annealing pots, 53 
two muffles, 41, 42 
Furnaces, muffle, 40-44 

GAS, case-hardening steel with, 127 
fiame, tempering by means of a, 

112 
muffle furnace for, 43 
Gaseous cooling agents, 104 
Gasteiger's patented fireplace, 47, 48 
Graphite, 4 
Graphitic carbon, 4 



Ti^ILES, annealing furnace for, 50-52 TTAMMER, straightening, 118 

F .• „ /•._.!. _i- ■.. 1 _. J .. I n swages, hardening and tem- 

])ering of, 154-156 



J- protection of teeth of, in harden 
ing, 124, 125 



Pire, open^ conversion of an, into a 
provisional furnace, 28, 29 



Hammers, hardening and tempering, 
of, 153, 154 



INDEX. 



175 



Hand chisels, forging, liardening and 
tempering of, 143, 114 
hammers, hardening and temper- 
ing of, 153, 154 
Hard-centred steel, 1 
Hard coke, 24, 25 

Hardened tools, investigation of de- 
fects of, 131-139 
Hardening, avoidance of failure in, 73 
bath, formation of steam in the, 

83, 84 
by means of a jet, 95 
by pressure, 104 
carbon, 3, 4 
changes in steel in, 62 
cause of changes in steel in, 63, 64 
cooling of tools in, and devices for 

this purpose, 83-96 
covering portions of the tools in, 

87, 88 
definition of, 62 
gradual progress of, 82, 83 
of tools which are to be hardened 
in their entirety, 73-79 
which are only to be par- 
tially hardened. 80-83 
of tool-steel in general, 62-73 
paste, 123 
property of steel of assuming fixed 

dimensions in, 65, 66 
powder, 123, 124 
steel, appliances for, 55-61 
water mixed with insoluble con- 
stituents, 100, 
101 
oils or fats, 101 
soluble constitu- 
ents, 98-100 
most suitable temperature of, 

97 
used for some time, value of, 98 
Heating appliances for steel. 23 
choice of fuel for, 23, 24 
long thin articles, appliance for, 

27-29 
steel in an open fire, drawbacks 

of, 34 
tools from the outside, 75. 76 
Hee^s. knives for stamping out, hard- 
ening and tempering of. 159 
Hot and cold chisels, forging, harden- 
ing and tempering of, 144 

INCHES, table for the conversion 
of centimeters to, 172 
Ingot steel, 1 

Investigation of defects of hardened 
tools, 131-139 



Iron, effect of hardening on the 
strength of, 140 
heating witli carbon 
on, 119 
occurrence of carbon in, 3, 4 
red hot, use of, for tempering, 112 
works, products of, employed in 
the manufacture of tools, 1 



K 



NIFE steel, 1 

Knives, circular, hardening and 
tempering of, 160 
for splitting leather, harden- 
ing and tempering of, 159 
long, furnace for tempering, 

114. 115 
stamping, hardening and 
tempering of, 159 



LEAD, mass for preventing, from 
adhering to tools, 59 
molten, disadvantages of 
heating steel in, 
58, 59 
partial tempering in, 
114 
use of, for hardening. 103 
Leather, knives for splitting, harden- 
ing and temper- 
ing of, 159 
stamping out, 
hardening and 
tempering o f , 
159 
Light, influence of, in judging the de- 
gree of temperature, 33. 34 
Lime, addition of, to hardening water. 

100 
Liquids used in quenching steel, 97- 
105 

MACHINE knives for cutting paper, 
hardening and tempering of, 159 
Magnet steel, 1, 14 

Mandrils for drawing metal cases and 
tubes, hardening and tempering of, 
164 
Manganese, 6 

influence of, upon the change in 

volume of steel, 72 
steel, actual, 6 
Martin steel, 1 
Mercury, use of, for hardening, 102, 

103 
Metal, hardening and tempering spiral 

drills for, 148, 149 
Metals, cast-iron crucible for melting, 
68 



170 



INDEX. 



Metals, molten, cooling wood-cutters 
in, 152 
tempering in, 110 
punches and dies for perforating 
holes in, hardening and tem- 
pering of, 1(52-164 
use of, for hardening, 102, 103 
Mild-centred steel, 1, 15 
Milling tools, hardening and temper- 
ing of, 153 
Molybdenum, 8, 9 

steel, 9 
MutHe furnace for eharcoal, 42, 43 
gas, 43 
in an open lire, 29, 30 
Muffles, paste for repairing cracks in, 

43 
Musbet steel, 12 

NAILS, tools for the manutacture of, 
hardening and tempering of, 165, 
166 
Natural steel, 1, 12 
Nickel, 8 

steel, 1, 8 

OIL, blazing otlwitii, 110 
tempering tools in. 111, 112 
Oils and fats, 102 

hardening water mixed 
with, 101 
Open fire, conversion of an, into a pro- 
visional furnace, 28, 29 
muffle built in an, 29, 30 
protection of steel from the 

blast in an, 32 
tempering in an, 112 
zones of heat in an, 27 

PAPER, knives for stamping out, 
hardening and tempering of, 
159 
machine knives for cutting, 
hardening and tempering of, 
159 
Pasteboard, knives for stamping out, 

hardening and tempering of, 159 
Phosphorus, 4 
Pillow-blocks and pivots, hardening 

and tempering of, 165 
Pipe-cutters, hardening and tempering 

of, 152 
Pipe-cutting knives, hardening and 

tempering of, 153 
Planing knives for wood, hardening 
and tempering of, 159 
forging and hardening 
of, 145 
Potash, addition of, to water, 98 



Potash, yellow prussiate of, 60 
Potassium chromale, 59, 60 
Powder for cooling, 81, 82 
, Puddled steel, 1 
i Punch steel, 1 
I heating a, 81 

Punches and (lies for perforating holes 
in metals, hardening 
. and tempering of, 

162-164 
hardening and temper- 
ing of, 160-162 

RE(iENKRATl()N of steel which 
has l)een spoiled in tiie tire, 129- 
131 
Keverberatory furnace, forging and 
hardening, 46 
small, 45 

with step grate, 
47 
ordinary forging, 44, 

45 
with (iasteiger's pat- 
ented fireplace, 
47, 48 
with muffle, 48 
Rivet chisels, forging, hardening and 

tempering of, 144 
Riveting hamniers, hardening and 

tempering of, 153, 154 
Roll sliear-knives, hardening and tem- 
pering of. 156 
turning knives, forging and hard- 
ening of, 146 
Rolling, changes in shape by, 20 
Rolls, hardening and tempering of, 
168-171 

SAL ammoniac, 99 
Salt, common, 59, 99 
mode of fusing, 60 
Salts, cast-iron crucible for melting, 68 
fused, heating steel in, 59-61 
mixture of, 59 
Sand, cooling with, 104 
hot, heating in, 76 

tempering by means of, 113 
Saws, furnace for heating, 39, 40 
Scales, 16 

Screw-dies, hardening and tempering 
of, 147, 148 
taps, hardening and tempering of, 
146, 147 
Scythe steel, 1 
Seams, 16, 17 
Self-hardened steel, 1, 12 
Shear steel, 1 



INDEX. 



1" 



Shear knives, furnace for heating, 39, 40 
hardening and tempering of, 

156-159 
long, heating of, 157, 158 
round and circular, harden- 
ing and tempering of, 156 
Silicon in crucible cast steel, 5 
Sledge hammers, hardening and tem- 
pering of, 153, 154 
Smith coal, 25, 26 
Soap water, effect of, 100 
Soda, addition of, to water, 98, 99 

carbonate of, 59 
Soft centred steel, 1, 15 
Soles, knives for stamping out, hard- 
ening and tempering of, 159 
Solid bodies as cooling agents, 104, 105 
Special steel, labels on, 10 
Special steels, 12-15 
Spindle, manner of packing a, for case- 
hardening, 121, 122 
Spiral drills for metal, hardening and 

tempering of, 148, 149 
Springs, hardening of, 103 

tempering of, 110 
Stamping knives, hardening and tem- 
pering of, 1 59 
Stamps and dies, hardening and tem- 
pering of, 162 
Steam, formation of, in the hardening 

bath, 83, 84 
Steel, accidental admixtures in, 4, 5 
action of blast upon, 31, 32 
adaptation of appliances for heat- 
ing of, 23 
appearance of fracture of, 17-19 
appliances for annealing, 48-55 

hardening, 55-61 
baked, 130 
blisters on the surfaces of the 

fractures of, 18 
burnt, 129 
carrier of the hardening capacity 

in, 3, 4 
case-hardening of, by cementation, 

127 
causes of changes in, in harden- 
ing, 63, 64 
changes in dimensions of, 64, 65 

in hardening, 62 
cracking of, 68, 69 
cracks on surface of, 16 
crucible cast, silicon in, 5 
dead, 130, 131 
decrease in volume of, 65 
defects of, which may be observed 
on the surfaces of the 
fractures of, 18, 19 

12 



Steel, defects of, which may show on 
the surface of. 16, 17 
delinition of, 3 
designations of, 1 , 2 
disadvantages of heating, in 

melted lead, 58, 59 
drawbacks of heating, in an open 

fire, 34 
edge cracks on surface of. 17 
effect of chromium upon the prop- 
erties of, 7, 8 
hardening on the strength 

of,. 140 
heating with carbon on, 

119 
nickel upon the proper- 
ties of, 8 
tempering on the strength 
and toughness of, 140, 
141 
tungsten upon the prop- 
erties of, 7 
fire treatment of, practice of the, 

22-48 
flaws in the centre of, 18, 19 

on the surfaces of the frac- 
tures of, 18 
furnace for annealing, in anneal- 
ing pots or annealing boxes, 
52 
hardened and unhardened, tablee; 
showing the influence of 
the various degrees of tem- 
perature upon, and their 
general application in prac- 
tice, 21, 22 
conditions on which the ap- 
pearance of the fracture of, 
depends, 21, 22 
increase in volume of, 67 
observations on the fracture 

of, 69 
tempering of, and devices for 
this purpose, 105-116 
heating appliances for, 23 

of. in fused salts, 59-61 
hints for the choice of suitable 

appliances for hardening, 56 
improving the properties of 

strength of. 140. 141 
influence of manganese upon the 

change in volume of. 72 
liquids used in quenching, 97-105 
magnet, 1, 14 
mild-centred, 1, 15 
modes of straightening. 117 
Mushet, 12 
natural, 1, 12 



178 



INDEX. 



Steel, observations on the fractnre of, 
witli regard to tlie structure in 
llie liardened and non-liardened 
state. 19-22 
overheated, 129, 130 
overheating of, in welding, 127 
I)n)i)crty of, of assuming fixed 
dimensions in hardening. 65, 66 
protection of, from tiie air in an- 
nealing. 49, 50 
from tiie blast in an 
open fire, 32 
roasted, 130 

rolled or forged, properties of, 140 
scales on surl'aces of, 16 
seams on surfoce of, 16, 17 
self-hardened, 1, 12 
shaping of, 22, 23 
soft-centred. 1 , 15 
spots on the surfaces of the frac- 
tures of, 18 
strains in. 65 

unhardened, conditions on which 
tlie appearance of the fracture 
of, dejiends, 20, 21 
very hard special turning, 12, 13 
welding of, 127-129 
which has been spoiled in the fire, 
regeneration of, 129-131 
Steels, special, 12-15 
Stone-working tools, hardening and 

tempering of, 165 
Straightening claw, 117, 118 

t'ools, 116-119 
Strain, force of, 67, 68 

in forming cracks, 70 
Strains, effect of, 71 
forging, 49 
in steel, 65 
Structure of hardened steel, conditions 
on which the appear- 
ance of the fracture of, 
depends, 21, 22 
unhardened steel, condi- 
tions on which the ap- 
pearance of the fracture 
of, depends, 20, 21 
Swages, annealing furnace for, 50-52 
hammer, hardening and temper- 
ing of, 154-156 

TABLE for the conversion of centi- 
meters to inches, 172 
Tal)les showing the influence of the 
various degrees of temi)eratnre upon 
hardened and unhardened steel, and 
their general api)lication in prac- 
tice, 21, 22 



Temper color, definition of, 62 

uneven appearance of, 
109 
Temper colore, recognition of the ad- 
vance of the heat by 
the, 106 
! rei|uirements for the ap- 

pearance of, 63 
I Temperature, inlluence of light, in 
judging tiie degree of, 33, 34 
Tempering by means of hot sand, 113 
effect of, on the strength and 

toughness of steel, 140, 141 
from the interior, 105-108 

assistance in, 
by heating 
from the out- 
side, 108 
in oil, device for. 111, 112 
long knives, furnace for, 114, 115 
modes of eflecting, 105 
of hardened steel and devices for 
this purpose, 105-116 
Tin, use of, for hardening, 103 
Titanium, 8. 9 
steel, 2, 9 
Tongs for handling balls, 167 

formation of cracks caused by, 85, 

86 
sliapes of, 86 
Tool, imparting special toughness to a, 
106 
main points to be considered in 

the construction of a, 79 
-steel, classification of, according 
to the degree of hardness 
and the purpose for which 
it is to be used, 9-15 
commercial, observations on 
the external ajjpear- 
ance of, 16-19 
stamps and labels on, 10 
composition of, and its classi- 
fication according to it, 
3-9 
danger of overheating and 

burning, 11, 12 
designations of hardness of, 10 
experiments regarding the 
cutting power of, 104, 105 
for definite purposes, 14, 15 
general designation of, 1 
groups of, 9, 10 
hardening of, in general, 62- 

73 _ 
intentional admixtures in, 5-9 
observations on the fracture 
of, 66 



INDEX, 



179 



Tool-steel, selection of, for a deter- 
mined purpose, 11 
standard for judging the fit- 
ness of a, 11 
structure of, 19 
Tools, avoidance of superficial scale- 
like separations on, 75 
boring out of, 79 
cause of distortion of, 117 
cooling of, in hardening and de- 
vices for this purpose, 83-96 
covering portions of, in harden- 
ing, 87, 88 
cracking of, 73-75 
cracks in, 134 
disc-like, tempering of, 112 
division of, into sections, 78 
experiments regarding the effi- 
ciency of, 136, 137 
flat, defects of, 133 
for the manufacture of nails, hard- 
ening and tempering of, 165, 
166 
general rule for cooling, 83 
hardened, immediate inspection 
of, 136 
increase in the toughness of, 

by boiling water, 110 
investigation of defects of, 

131-139 
uneven degree of hardness of, 
134 
heating of, from the outside, 75, 
76 
in use, 138, 139 
so that the air is abso- 
lutely excluded, 57 
hints for the inspection of, 132- 

135 
hollow, hardening of, 95, 96 
large, tempering of, 114, 115 
long, straightening of, 117 
mass for preventing lead from 

adhering to, 59 
milling, hardening and tempering 

of, 153 
of small cross section, tempering 

of, 108 
partial tempering of, in hot sand, 

114 
partially hardened, error in tem- 
pering, 116 
paste of carbonaceous substances 

for the protection of, 125, 126 
perforated, tempering of, 112 
products of iron works employed 

in the manufacture of, 1 
requisites in tempering, 109, 110 



Tools, roasted or baked, 135 

severance of corners and edges of, 

132 
small, cracks in, 132, 133 
soft skin on the surface of, 135 
stone - working, hardening and 

tempering of, 165 
straightening of, 116-119 

by uneven heating 
and cooling, 
118, 119 
tempering of, in molten metals, 
110 
oil. 111, 112 
thin, flat, straightening of, 117 
to be partially hardened, groups 

of, 80, 81 
unevenly heated, cooling of, 125 
unequal cooling of, 84, 85 
uniform degree of insufficient 

hai-dness of, 135 
use of water for hardening, 89-96 
which are only to be partially 
hardened, hardening 
of, 80-83 
to be hardened in their 
entirety, hardening of, 
73-79 " 
with engraved surfaces, crumbling 

of, 138 
working under especially high 
pressure, hardening of, 77 
Tungsten, 6, 7 

steel, 1 
Turning knives, foiling and harden- 
ing of, 145 
steel, very hard special, 12, 13 
Tuyeres for open fires, 27 



TTNIVERSAL steel, 



V 



ANADTUM, 8, 9 
steel, 1, 9 



WATER, ascending, use of, for 
hardening, 93, 94 
falling, use of, for hardening, 

90-92 
hot, heating in, 76 
increase in the heat-conducting 

power of, 97, 98 
pure, 97, 98 

running, use of, for hardening, 
89 
Weld steel, 1, 2 
Weldable ingot steel, 2 
Welding of steel, 127-129 



180 



INDEX. 



Wood-cutters, cooling of, in molten | T/'PXLOW prnseiate of potash, 60 

metals, 152 JL 

Wood, planing and cutting knives 



for, hardening and tempering of, 
159 



f7INC, use of, for hardening, lOii 



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AMATEUR MECHANICS' WORKSHOP: 

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ARLOT.— A Complete Guide for Coach Painters : 

Translated from the French c'" M. Arlot, Coach Painter, for 
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ARROWSMITH.— Paper-Hanger's Companion : 

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BRONGNIART. — Coloring and Decoration of Ceramic Ware. 
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BAIRD. — The American Cotton Spinner, and Manager's and 
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'3AIRD. — Standard Wages Computing Tables : 

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BAKER. — The Mathematical Theory of the Steam - Engine : 
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BARLOW.— The History and Principles of Weaving, by 
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BARR.— A Practical Treatise on the Combustion of Coal: 
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BARR. — A Practical Treatise on High Pressure Steam Boilers: 
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8AUERMAN.— A Treatise on the Metallurgy of Iron : 
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BRANNT.— The Metallic Alloys: A Practical Guide 

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BELL. — Carpentry Made Easy: 

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BEMROSE. — Manual of Buhl-work and Marquetry: 

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csEMROSE.— Manual of Wood Carving: 

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BILLINGS.— Tobacco : 

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BIRD. — Tlie American Practical Dyers' Companion: 
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BLINN. — A Practical Workshop Companion for Tin, Sheet- 
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BOOTH. — Marble Worker's Manual: 

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BOOTH and MORFIT.— The Encyclopaedia of Chemistry, 
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BRAM WELL.— The Wool Carder's Vade-Mecum. 

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BRANNT. — A Practical Treatise on Animal and Vegetable 
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BRANNT.— A Practical Treatise on the Manufacture of Soap 
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BRANNT.— India Rubber, Gutta Percha and Balata: 

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BROWN. — Five Hundred and Seven Mechanical Movements: 
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BUCKMASTER.— The Elements of Mechanical Physics : 
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BULLOCK. — The American Cottage Builder : 

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BULLOCK. — The Rudiments of Architecture and Building : 
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BURGH. — Practical Rules for the Proportions of Modem 
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BYLES. — Sophisms of Free Trade and Popular Political 

Economy Examined. 

By a Barrister (Sir John Barnard Byles, Judge of Common 

Pleas). From the Ninth English Edition, as published by the 

Manchester Reciprocity Association. i2nio. . . . Sl-25 

eOWMAN.— The Structure of the Wool Fibre in its Relation 
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Being the substance, with additions, of Five Lectures, delivered at 
"he request of the Council, to the members of the Bradford Technical 
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8vo. 



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BYRNE. — Hand-Book for the Artisan, Mechanic, and Eniji- 
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Comprising the Grinding and Sharpening of Cutting Tools, Abia-.ve 
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BYRNE.— Tne Practical Metal- Worker's Assistant: 
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BYRNE.— The Practical Model Calculator: 

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CABINET MAKER'S ALBUM OF FURNITURE. 

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Oblong, Svo $1.50 

CALLINGHAM.— Sign Writing and Glass Embossing: 

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CAMPIN. — A Practical Treatise on Mechanical Engineering: 
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shop Machinery, Mechanical Manipulation, Manufacture of Steam- 
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Ores. By Fpancis Campin, C. E. To which are added. Observations 
00 the Construction of Steam Boilers, and Remarks upon Furnaces 
used for Smoke Prevention ; with a Chapter on Explosions. By R, 
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CAREY.— A Memoir of Henry C. Carey. 

By Dr. \Vm. Ki.dku. With a portrait. 8vo., cloth . . 75 

CAREY.— The Works of Henry C. Carey: 

Harmony of Interests: Agricultural, Manufacturing and Commer- 
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Manual of Social Science. Condensed from Carey's " Principles 
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Principles of Social Science. 3 volumes, 8vo. . . 57-50 
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The Unity of Law : As Exhibited in the Relations of Physical, 
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CLARK. — Tramways, their Construction and Working : 

Emlaracing Comprehensive History of the System. With an ex- 
haustive analysis of the various modes of traction, including horse- 
power, steam, heated water and compressed air ; a description of the 
varieties of Rolling stock, and ample details of cost and working ex- 
penses. By D. KiNNEAR Clark. Illustrated by over 200 wood 
engravings, and thirteen folding plates. I vol. 8vo. . ^7.50 

COLBURN.— The Locomotive Engine : 

Including a Description of its Structure, Rules for Estimating its 
Capabilities, and Practical Observations on its Construction and Man 
agement. By Zerah Colburn. Illustrated. i2mo. . $1.00 

COLLENS.— The Eden of Labor; or, the Christian Utopia, 
By T. Wharton Collens, author of " Humanics," " The Historj 
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COOLEY. — A Complete Practical Treatise on Perfumeiy : 
Being a Hand-book of Perfumes, Cosmetics and other Toilet Articlei 
With a Comprehensive Collection of Formulae. By Arnold _' 
CoOLEY. i2mo. ........ $1.50 

COOPER.— A Treatise on the use of Belting for the Tranu 
mission of Power. 
With numerous illustrations of approved and actual methods of ar 
ranging Main Driving and Quarter Twist Belts, and of Belt Fasten 
ings. Examples and Rules in great number for exhibiting and cal- 
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Practical Directions for the Treatment, Care and Management o^ 
Belts. Descriptions of many varieties of Beltings, together witfi 
chapters on the Transmission of Power by Ropes ; by Iron and 
Wood Frictional Gearing; on the Strength of Belting Leather; and 
on the Experimental Investigations of Morin, Briggs, and others. By 
John H. Cooper, M. E. 8vo $3-50 

CRAIK. — The Practical American Millwright and M^ler. 

By David Craik, Millwright. Illustrated by numerous wood en- 
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CROSS. — The Cotton Yarn Spinner: 

Showing how the Preparation should be arranged for Different 
Counts of Yarns by a System more uniform than has hitherto been 
practiced; by having a Standard Schedule from which we make all 
our Changes. By Richard Cross. 122 pp. i2mo. . 75 

CRISTIANI. — A Technical Treatise on Soap and Candles: 

With a Glance at the Industry of Fats and Oils. By R. S. Cris- 
TIANI, Chemist. Author of " Perfumery and Kindred Arts." . Illus- 
trated by 176 engravings. 581 pages, 8vo. $it;.oo 

COURTNEY.— The Boiler Maker's Assistant in Drawing, 
Templating, and Calculating Boiler Work and Tank 
Work, etc. 
Revised by D. K Clark. 102 ills. Fifth edition. . . 80 
COURTNEY.— The Boiler Maker's Ready Reckoner: 

With Examples of Practical Geometry and Templating. Revised by 
D. K. Clark, C. E. 37 illustrations. Fifth edition. • $i-6o 

DAVIDSON.— A Practical Manual of House Painting, Grain- 
ing, Marbling, and Sign- Writing: 
Containing full information on the processes of House Painting in 
Oil and Distemper, the Formation of Letters and Practice of Sign- 
Writing, the Principles of Decorative Art, a Course of Elementary 
Drawing for House Painters, Writers, etc., and a Collection of Useful 
Receipts. With nine colored illustrations of Woods and Marbles, 
and nutnerous wood engravings. By Ellis A Davidson. lamo. 

$2.00 

DAVIES.— A Treatise on Earthy and Other Minerals and 
Mining: 
By D. C. Davies, F. G. S., Mining Engineer, etc. Illustrated by 
76 Engravings. l2mo. . . . . • • • ^5 °<^ 

DAVIES.— A Treatise on Met-^lliferous Minerals and Mining: 
Bv D. C. Davies, F. G. S , Mining Engineer, Examiner of Mines, 
Quarries and Collieries. Illustrated by 148 engravings of Geological 
Formations, Mining Operations and Machinery, drawn from the 
practice of all parts of the world. Fifth Edition, thoroughly Revised 
and much Enlarged by his son, E. Henry Davies. i2mo., 524 
pages • • ^5-00 

DAVIES.— A Treatise on Slate and Slate Quarrying: 

Scientific, Practical and Commercial. By D. C. Davies, F. G. S., 
Mining Engineer, etc. W^ith numerous illustrations and folding 
plates. ;2mo. .....••• $l.20 

DAVIS.— A Practical Treatise on the Manufacture of Brick, 

Tiles and Terra-Cotta : 

Including Stiff Clay, Dry Clay, Hand Made, Pressed or Front, and 

Roadway Paving Brick, Enamelled Brick, with Glazes and Colors, 

Fire Brick and 'Blocks. Silica Brick, Carbon Brick, Glass Pots, Re- 



io IlENRV CAREY BAIRD & CO.'S CATALOGUE. 



torts, Arcliitectural Terra-Cotta, Sewer Pipe, Drain Tile, Glazed and 
Unglazeil Rooting Tile, Art Tile, Mosaics, and Imitation of Intarsia 
or Inlaid Surfaces. Comprising every product of Clay employed in 
Architecture, Engineering, and the Blast Furnace. With a Detailed 
Description of the Different Clays employed, the Most Modern 
Machinery, Tools, and Kilns used, and the Processes for Handling, 
Disintegrating, Tempering, and Moulding the Clay into Shape, Dry- 
ing, Setting, and Burning. By Charles Thomas Davis. Third Edi- 
tion. * Revised and in great part rewritten. Illustrated by 261 
engravings. 662 pages ....... $5.00 

DAVIS. — A Treatise on Steam-Boiler Incrustation and Meth- 
ods for Preventing Corrosion and the Formation of Scale: 
By Charles T. Davis. Illustrated by 65 engravings. 8vo. 
DAVIS. — The Manufacture of Paper: 

Being a Description of the various Processes for the Fabrication, 
Coloring and Finishing of every kind of Paper, Including the Dif- 
ferent Raw Materials and the Methods for Determining their Values, 
the Tools, Machines and Practical Details connected with an intelli- 
gent and a profitable prosecution of the art, with special reference to 
the best American Practice. To which are added a History of Pa- 
per, complete Lists of Paper- Making Materials, List of American 
Machines, Tools and Processes used in treating the Raw Materials, 
and in Making, Coloring and Finishing Paper. By CHARLES T. 
Davis. Illustrated by 156 engravings. 608 pages, Svo. ;$6.oo 

DAVIS.— The Manufacture of Leather: 

Being a Description of all the Processes for the Tanning and Tawing 
with Bark, Extracts, Chrome and all Modern Tannages in General 
Use, and the Currying, Finishing and Dyeing of Every Kind of Leather ; 
Including the Various Raw Materials, the Tools, Machines, and all 
Details of Importance Connected with an Intelligent and Profitable 
Prosecution of the Art, with Special Reference to the Best .American 
Practice. To which are added Lists of American Patents (1884-1897) 
for Materials, Processes, Tools and Machines for Tanning, Currying, 
etc. By Charles Thomas Davis. Second Edition, Revised, and 
in great part Rewritten. Illustrated by 147 engravings and 14 Sam- 
ples of Quebracho Tanned and Aniline Dyed I.eathers. 8vo, cloth, 

712 pages. Price 1750 

DAWIDOWSKY— BRANNT.— A Practical Treatise on the 

Raw Materials and Fabrication of Glue, Gelatine, Gelatine 

Veneers and Foils, Isinglass, Cements, Pastes, Mucilages, 

etc. : 

Eased upon Actual Experience. By F. Dawidowsky, Technical 

Chemist. Translated from the German, with extensive addition^, 

including a description of the most Recent American Processes, l)y 

William T. Brannt, Graduate of the Royal Agricultural College 

of Eldena, Prussia. 35 Engravings. l2mo. . . . ^$2.50 

DE GRAFF.— The Geometrical Stair-Builders' Guide: 

being a Plain Practical System of Hand-Railing, embracing all its 
necessary Details, and Geometrically Illustrated by twenty-two Steel 
Engravings; together with the use of the most approved principles 
nf Practical Geometry. By Simon De Graff, Architect. (Scarce.) 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



DE KONINCK— DIETZ.— A Practical Manual of Chemical 
Analysis and Assaying : 
As applied to the Manufacture of Iron from its Ores, and to Cast Iron, 
Wrought Iron, and Steel, as found in Commerce. By L. L. Dk 
KoNiNCK, Dr. Sc, and E. Dietz, Engineer. Edited with Notes, by 
Robert Mallet, F. R. S., F. S. G., M. I. C. E., etc. American 
Edition, Edited with Notes and an Appendix on Iron Ores, by A. A. 
Fesquet, Chemist and Engineer. i2mo. . . . $1.50 

DUNCAN.— Practical Surveyor's Guide: 

Containing the necessary information to make any person of com* 
mon capacity, n finished land surveyor without the aid of a teacher 
By Andrew Di-ncan. Revised, 72 engravings, 214pp. l2rao. $1.50 

DUPLAIS. — A Treatise on the Manufacture and DistillatioD 
of Alcoholic Liquors : 
Comprising Accurate and Complete Details in Regard to Alcohol 
from Wine, Molas'^es, Beets, Grnin, Rice, Potatoes, Sorghum, Aspho- 
del, Fiuits, etc.; with the Distillation and Rectification of Brandy. 
Whiskfey, Rum, Gin, Swiss Absinthe, etc., the Prepar?tion of Aro- 
matic Waters, Volatile Oils or Essences, Sugars, Syrups, Aromatic 
Tinctures, Liqueurs, Cordial Wines, Effervescing Wines, etc., the 
Ageing of Brandy and the improvement of Spirits, with Copioaa 
Directions and Tables for Testing and Reducing Sjiirituous Liquors, 
etc.,, etc. Translated and Edited from the French of MM. DuPLAlS, 
By M. McKennie, M. D. Illustrated 743 pp. 8vo. ^15.00 

DYER AND COLOR-MAKER'S COMPANION : 

Containing upwards of two hundred Receipts for making Colors, on 
the most approved principles, for all the various styles and fabrics now 
in evistence ; with the Scouring Process, and plain Directions for 
Preparing, Washing-off, and Finishing the Goods. l2mo. $i CO 

EIDHERR.— The Techno-Chemical Guide to Distillation: 
A Hand-Book for the Manufacture of Alcohol and Alcoholic Liquors, 
including the Preparation of Malt and Compressed Yeast. Edited 
from the German of Ed. Eidherr. Fully illustrated. (In preparation.) 

EDWARDS. — A Catechism of the Marine Steam-Engine, 
For the use of Engineers, Firemen, and Mechanics. A Practical 
Work for Practical Men. By Emory Edwards, Mechanical Engi- 
neer. Illustrated by sixty three Engravmgs, including examples of 
the most modern Engine^. Third edition, thoroughly revised, with 
much additional matter. 1 2 mo. 414 pages . . ^2 oc 

EDWARDS. — Modern American Locomotive Engine3, 
Their Design, Construction and Management. By Emory EdwardS,. 
Illustrated l2mo ^2-<» 

EDWARDS.— The American Steam Engineer: 

Theoretical and Practical, with examples of the latest and most ap- 
proved American practice in the design and construction of Steam 
Engines and Boilers. For the use of engineers, machinists, boiler- 
tP-^kers, and engineering students. By Emory Edwards. Fully 
illustrated, 419 pages. i2mo. - . . . $2.Sfi 



12 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

EDWARDS. — Modern American Marine Engines, Boilers, and 

Screw Propellers, 
Their Design and Construction. Showing the iVesent Praaice ot 
the mo^t Eminent Engineers and Marine Engine Builders in the 
United States. Ilkistrated hv 30 large and elaborate plates. 410. 55-OC 
EDWARDS.— The Practical Steam Engineer's Guide 

In the Design, Construction, and Management of American Stationary, 
Portable, and Steam P'ire- Engines, Steam Pumps, Boilers, Injector^ 
Governors, Indicators, Pistons and Rings, Safety Valves and Steam- 
Gauges. For the use of Engineers, Firemen, and Steam Users. By 
Emory Edwards. Illustrated by 119 engravings. a20 pages. 
l2mo. .......... 52 50 

EISSLER.— The Metallurgy of Gold: 

A Practical Treatise on the Metallurgical Treatment of Gold-Bear- 
ing Ores, including the Processes of Concentration and Chlorination, 
and the Assaying, Melting, and Refining of Gold. By M. Eissler. 
With 132 Illustrations. l2mo. ..... $7.50- 

EISSLER.— The Metallurgy of Silver : 

A Practical Treatise on the Amalgamation, Roasting, and Lixivintii in 
of Silver Ores, including the Assaying, Melting, and Refining of 
Silver Bullion. By M. Eissler. 124 Illustrations. 336 pp. 
l2mo. .......... ^25. 

ELDER. — Conversations on the Principal Subjects of Political 
Economy. 
By Dk. William Elder. 8vo ;?2.5o 

ELDER.— Questions of the Day, 

Economic and Social. By Dr. William Elder. 8vo. . ;83.00 
ERNI AND BROWN.— Mineralogy Simplified. 

Easy Methods of Identifying Minerals, including Ores, by Means of 
the Blow-pipe, by Flame Reactions, bv Humid Chemical Analysis, 
and by Physical Tests. By Henri Erni, A. M., M. D. Third Edi- 
tion, revised, re-arranged and with the addition of entirely new matter, 
including Tables for the Determination of Minerals by Chemical and 
Pyrognostic Cliaracters, and by Physical Characters. By Amos P. 
Brown, E. M., ph. D. 350 pp., illustrated by 96 engravings, pocket- 
book form, full flexible morocco, gilt edges . . . ^2.50 
FAIRBAIRN.— The Pnnciples of Mechanism and Machinerj 
of Transmission • 
Comprising the Prniciples of Mechanism, Wheels, and Pullevs, 
Strength and Proportions of Shafts, Coupling of Shatts, and Engag 
ing and Disengaging Gear. By SiR William Fairbairn, Bait 
C. E. Beautifully illustrated by over 150 woodcuts. In one 

volume. 1 2mo $2.00 

FLEMING. — Narrow Gauge Railways in America. 
A Sketch of their Rise, Progress, and Success. Valuable Statistics' 
IS to (Jiades, Curves, Weight of Rad, Locomotives, Cars, efc. By 
Howard Fleming. Illustrated, 8vo. . . . . $1 00 
FORSYTH.— Book of Designs for Headstones. Mural, and 
oth&r Monuments : 
Containing 78 Designs. By James Forsyth. With an Introduction 
'jy Charles Boutell, M. A. 4 to., cloth . . $3-50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 13 



FRANKEL— HUTTER.— A Practical Treatise on the Manu« 
facture of Starch, Glucose, Starch-Sugar, and Dextrine: 
Based on the German of Ladislaus Von Wagner, Professor in the 
Royal Technical High School, BudaPesl, Hungary, and other 
authorities. By Julius Frankel, Graduate ol the Polytechnic 
School of Hanover. Edited by Robert Hutter, Chemist, Practical 
Manufacturer of Starch-Sugar. Illustrated by 58 engravings, cover- 
ing every branch of the subject, including examples of the most 
Recent and Best American Machinery. 8vo., 344 pp. . Sj So 

GARDNER.— The Painte."s Encyclopgedia : 
Containing Definitions of ail Important Words in the Art of Plain 
and Artistic Painting, with Details of Practice in Coach, Carriage, 
Railway Car, House, Sign, and Ornamental Painting, including 
Graining, Marbling, Staining, Varnishing, Polishing, Lettering, 
Stenciling, Gilding, Bronzing, etc. By Franklin B. Gardner. 
158 Illustrations. i2mo. 427 pp. ..... 32. OC 

GARDNER.— Everybody's Paint Book: 

A Complete uuide to the Art of Outdoor and Indoor Painting. 38 
illustrations l2mo, 183 pp. ...... 5 LOO 

GEE. — The Jeweller's Assistant in the Art of Working in 
Gold: 
A Practical Treatise foi Masters and Workmen. i2mo. . ^j-OO 

GEE.— The Goldsmith's Handbook : 

Containing full instructions for the Alloying and Working of Gold, 
including the Art of Alloying, Melting, Reducing, Coloring, Col 
lecting, and Refining; the Processes of Manipulation, Recovery of 
Waste ; Chemical and Physical Properties of Gold ; with a New 
System of Mi.>;ing its Alloys ; Solders, Enamels, and other Useful 
Rules and Recipes. By George E. Gee. i2mo. » • 1^1.25 

GEE.— The Silversmith's Handbook : 

Containing full instructions for the Alloying and Working of Silver, 
including the different modes of Refinir-^ and Melting the Metal ; its 
Solders ; the Preparation of Imitation Alloys ; Methods of Manipula- 
tion ; Prevention of Waste ; Instructions for Improving and Finishing 
the Surface of the Work ; together with other Useful Information and 
Memoranda. By George E. Gee. Illustrated. i2mo. Si. 25 

GOTHIC ALBUM FOR CABINET-MAKERS: 

Designs for Gothic Furniture. Twenty-three plates. Oblong $1.50 

GRANT. — A Handbook on the Teeth of Gears : 

Their Curves, Properties, and Practical Construction. By George 
B. Grant. Illustrated. Third Edition, enlarged. Svo. ^i.oo 

GREENWOOD.— Steel and Iron: 

Comprising the Practice and Theory of the Several Methods Pur- 
sued in their Manufacture, and of their Treatment in the Rolling- 
Mills, the Forge, and the Foundry. By William Henry Green- 
wood, F. C. S. With 97 Diagrams, 536 pages. l2mo. i^I.JS 



14 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



GREGORY. — Mathematics for Practical Men: 

AHapied to the rursuits of Surveyors, Architects, Mechanics, and 
Civil Ewgineers. By Oi.iNTHUS Gregory. 8vo., plates $3.00 

GRISWOLD. — Railroad Engineer's Pocket Companion for thi 
Field : 
Coiiipri^iiig Rules for Calculating Deflection Distaiicrs and Angles 
Tangential Distances and Angles, and all Necessary T.ibles for 1-ji 
gineers; also the Art of Levelling from Pieliininaiy Survey to "iht 
Construction of Railroads, intended Expres-ly for the Young Kn 
gineer, together with Numerou-- Vnluahle Rule;, and lixamnles. By 
W. Griswuli). i2mo., tucks ..... $1.50 

GRUNER. — Studies of Blast Furnace Phenomena: 

By .\L L. Gruner, President of the General Council of Mines oi 
France, and lately ProfesMir ui Metallurgy at the Ecole des Mines. 
Translated, with the author's sanction, with an /appendix, by L. D. 
B. Gordon, F. R. S. E.. F. G. S. 8vo. . . . $2.50 

Hand-Book of Useful Tables for the Lumberman, Farmei and 
Mechanic : 
Containing Accurate Tables of Logs Reduced to Inch Board Meas- 
ure, Plank, Scantling and Timber Measure; Wages and Rent, by 
Week or Month; Capacity of Granaries, Bins and Cisterns; Land 
Measure, Interest Tables, with Directions for Finding the Interest on 
any sum at 4, 5, 6, 7 and 8 per cent., and many other Useful Tables. 
32 mo., boards. 186 pages .25 

HASERICK.— The Secrets of the Art of Dyeing Wool, Cotton, 
and Linen, 
Including Bleachlr^g an'^. Coloring Wool and Cotton Hosiery and 
Random Yarns. A Treatise based on Economy and Practice. By 
E. C. Haserick. Illustrated by 323 Dyed Patterns of the Varni 
or fabrics. 8vo. ........ J^5-00 

HATS AND FELTING: 

A Practical Treatise on their Manufacture. By a Practical Hatici 
Illustrated by Drawings of Machinery, etc. 8vo. . . $1.25 

HERMANN. — Painting on Glass and Porcelain, and Enamel 
Painting: 
A Complete Introduction to the Preparation of all the Colors and 
Fluxes Used for Painting on Glass, Porcelain, Enamel, Faience and 
Stoneware, the Color Pastes and Colored Glasses, together with a 
Minute Description of the Firing ot Colors and Enamels, on the 
Basis of Personal Practical Experience of the Art up to Date. 18 
illustrations. Second edition. ..... 

HAUPT.— Street Railway Motors: 

With Descriptions and Cost of Plants and Operation of the Variou* 
Systems now in Use. I9t«'> , . . . $1-75 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 15 



HAUPT. — A Manual of Engineering Specifications and Con- 
tracts. 

By Lewis M. Haupt, C. E. Illustrated with numerous maps, 
328pp. 8vo ;5!3 00 

HAUPT. — The Topographer, His Instruments and Methods. 
By Lewis M. Haupt, A. M., C. E. Illustrated with numerous 
plates, maps and engravings. 247 pp. Svo. , . . $3.00 

HUGHES. — American Miller and Millwright's Assistant: 
By William Carter Hughes. i2mo. .... $1.50 

HULME. — Worked Examination Questions in Plane Geomet • 
rical Drawing : 
For the Use of Candidates for tlie Royal Military Academy, Wool- 
wich ; the Royal Military College, Sandhurst ; the Indian Civil En- 
gineering College, Cooper's Hill ; Indinn Public Works and Tele- 
graph Departments; Royal Marine Litjht Infantry; the Oxford and 
Cambridge Local Examinations, etc. By F. Edward Hulme, F. L. 
S., F. S. A., Art-Master Marlborough College. Illustrated by 300 
examples. Small quarto tl.?o 

JERVIS.— Railroad Property: 

A Treatise on the Construction and Management of Railways; 
designed to afford useful knowledge, in the popular style, to the 
holders of this class of property ; as well as Railway Managers, Offi 
cers, and Agents. By JoHN B. Jervis, late Civil Engineer of the 
Hudson River Railroad, Croton Aqueduct, etc. i2mo., cloth 52.0c 

KEENE.— A Hand-Book of Practical Gauging: 

For the Use of Beginners, to which is added a Chapter on Disidla 
tion, describing the process in operation at the Custom-House fo» 
ascertaining the Strength of Wines. By James B. Keene, of H. M. 
Customs. Svo. ........ ^I 00 

KELLEY.— Speeches, Addresses, and Letters on Industrial and 
Financial Questions : 
By Hon. William D. Kelley, M. C. 544 pages, Svo. . iz.^a 

KELLOGG. — A New Monetary System : 
The only means of Securing ihe respective Rights of Labor and 
Properly, and of Protecting the Public from Financial Revulsions. 
By Edward Kellogg. i2mo. Paper cover, $1.00. Bound in 
cloth ff-25 

KEMLO.— Watch-Repairer's Hand-Book : 
Bem'4 a Complete Guide to the Young Beginner, in Taking Apar 
Pulling Together, and Thoroughly Cleaning the English Lever am! 
■ >ther Foreign Watches, and all American Watches. By F. KfiMLo, 
Practical WafrVirnaker. With illustrations. i2mo. ^81.25 



X6 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



KENTISH.— A Treatise on a Box of Instruments, 

And the Slide Rule ; with the Theory of Trigonometry and Loga- 
rithms, including Practical Geometry, Surveying, Measuring of Tim. 
ber, Cask and Malt Gauging, Heights, and Distances. By Thoma* 
Kentish. In one volume. i2mo. , . ■ . . ;^i.oo 

KERL. — The Assayer's Manual: 

An Abridged Treatise on the Docimastic Examination of Ores, and 
Furnace and other Artificial Products. By Bruno Kerl, Professor 
in the Royal School of Mines. Translated from the German by 
William T. Brannt. Second American edition, edited with Ex- 
tensive Additions by F. Lynwood Garrison, Men>ber of the 
American Institute of Mining Engineers, etc. Illustrated by 87 en- 
gravings. 8vo. (Scarce.^ 
KICK.— Flour Manufacture. 

A Treatise on Milling Science and Practice. By Frederick Kick 

Imperial Regierungsrath, Professor of Mechanical Technology in tht 

.imperial German Polytechnic Institute, Prague. Translated from 

the second enlarged and revised edition with supplement' by H. H. 

P. PowLES, Assoc. Memb. Institution of Civil Engineers. Illustrated 

with 28 Plates, and 167 Wood-cuts. 367 pages. 8vo. . ;gio.oo 

KINGZETT.— The History, Products, and Processes of the 

Alkali Trade : 

Including the most Recent Improvements. By Charles Thomasi 

''•v,-7KTr Cor>sultinr; Chemist. With 23 illustrations. Svo. ^2.50 

KIRK.— The Cupola Furnace : 

A Practical Treatise on the Construction and Management of Foundry 
Cupolas. By Edward Kirk, Practical Moulder and Melter, Con- 
sulting Expert in Melting. Author of " The Founding of Metals." 
Illustrated by 78 engravings. Svo. 379 pages. . . ^53-50 

LANDRIN.— A Treatise on Steel : 

Cuniprisuig its Theory, Metallurgy, Properties, Practical Working, 
and Use. By M. H. C. Landrin, Jr. From the French, by A. A. 
Fesquet. i2mo ^2.50 

LANGBEIN.— A Complete Treatise on the Electro-Deposi. 
tion of Metals : 
Comprising Electro-Plating and Galvanoplastic Operations, the De- 
position of Metals by the Contact and Immersion Processes, the Color- 
ing of Metals, the Methods of Grinding and Polishing, as well as 
Descriptions of the Electric Elements, Dynamo-Electric Machines, 
Thermo- Piles and of the Materials and Processes used in Every De- 
partment of the Art. F'rom the German of'DR. George Langbein, 
with additions by Wm. T. Brannt. Fourth Edition, thoroughly revised 
and much enlarged. 150 Engravings. 590pages. 8vo. 1902. ^.OO 

LARDNER.— The Steam-Engine : 

For the Use of Beginners. Illustrated. i2mo. . . , _6o 

LEHNER.— The Manufacture of Ink: 

Comprising the Raw Materials, and the Preparation df W'jting, 
Copying and Hektograph Inks, Safety Inks, Ink Extracts and Pow- 
ders, etc. Translated from the German of SiGMUND Lehner, with 
additions by William T. Brannt. Illustrated. i2mo. $2.00 



HENRY CAREY BAIRD & f^O.'S CATALOGUR 17 

LARKIN. — The Praciicai Brass and Iron Founder's Guide.- 
A Concise Treatise on Brass Founding, Moulding, tlie Metals and 
their Alloys, etc. ; to which are added Recent Improvements in the 
Manufacture of Iron, Steel by the Bessemer Process, etc., etc. By 
James Larkin, late Conductor of the Brass Foundry Department ia 
Reany, Neafie & Co.'s Penn Works, Philadelphia. New edition, 
revised, with extensive additions. 414 pages. i2mo. , $2.50 

LEROUX. — A Practical Treatise on the Manufacture of 
Worsteds and Carded Yarns : 
Comprising Practical Mechanics, with Rules and Calculations applied 
to Spinning; Sorting, Cleaning, and Scouring Wools; the English 
and French Methods of Combing, Drawing, and Spinning Worsteds, 
and Manufacturing Carded Yarns. Translated from the French of 
Charles Leroux, Mechanical Engineer and Superintendent of a 
Spinning-Mill, by HoRATio Paine, M. D., and A. A. Fesquet, 
Chemist and Engineer. Illustrated by twelve large Plates. To which 
is added an Appendix, containing Extracts from the Reports of the 
International Jury, and of the Artisans selected by the Conimitte; 
appointed by the Council of the Society of Arts, London, on Woolen 
and Worsted Machinery and Fabrics, as exhibited in the Paris Uni- 
versa! Exposition, 1867. 8vo. . . . . . $<ioci 

LEFFEL.— The Construction of Mill-Dams : 
Comprising also the Building of Race and Reservoir Embankments 
and Head-Gates, the Measurement of Streams, Gauging of Water 
Supply, etc. By James Leffel & Co. Illustrated by 58 engravings. 
8vo ^2.50 

LESLIE.— Complete Cookery: 
Directions for Cookery in its Various Branches. By Miss Leslie. 
Sixtieth thoasand. Thoroughly revised, with the addition of l^evi 
Receipts. i2mo. . . . . . . . . ^51.50 

LE VAN. — The Steam Engine and the Indicator : 

Their Origin and Progressive Development ; including the Most 
Recent Examples of Steam and Gas Motors, together with the Indi- 
cator, its Principles, its Utility, and its Application. By William 
Barnet Le Van. Illustrated by 205 Engravings, chiefly of Indi. 
cator-Cards. 469 pp. 8vo. $4-00 

LIEBER.— Assayer's Guide ; 
Or, Practical Directions to Assayers, Miners, and Smelters, for the 
Tests and Assays, by Heat and by Wet Processes, for the Ores of all 
the principal Metals, of Gold and Silver Coins and Alloys, and of 
Coal, etc. By Oscar M. Lieber. Revised. 283 pp. i2mo. ^1.50 

Cockwood's Dictionary of Terms : 

Used in the Practice of Mechanical Engineering, embracing those 
Current in the Drawing Office, Pattern Shop, Foundry, Fitting, Turn- 
ing, Smith's and Boiler Shops, etc., etc., comprising upwards of Six 
Thousand D'^finitions. Edited by a Foreman Pattern Maker, author 
i^f " Patterr Making." 417 pp. i2mo. . . . $3.00 



18 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

LUKIN.— The Lathe and Its Uses : 

Or Instruction in the Art of 'lurnint^ Wood and Metal. Including 
a Description of the Most Modern Appliances for the Ornamentation 
of Plane and Curved Surfaces, an Entirely Novel Form of Lathe 
for Eccentric and Rose-Engine Turning; A Lathe and Planing 
Machine Combined; and Other Valuable Matter Relating to the 
Art. Illustrated by 462 engravings. Seventh edition. 315 pages. 

Svo $4-25 

MAIN and BROWN. — Questions on Subjects Connected with 

the Marine Steam-Engine : 

And Examination Papers; with Hints for their Solution. By 

Thomas J. Main, Professor of Mathematics, Royal '^Javal College, 

and Thomas Brown, Chief Engineer, R. N. i2nio., cloth . $1.00 

MAIN and BROWN. — The Indicator and Dynamometer: 

With their Practical Applications to the Steam-Engine. By THOMAS 
J, Main, M. A. F. R., Ass't S. Professor Royal Naval College, 
Portsmouth, and Thomas Brown, Assoc. Inst. C. E., Chief Engineer 
R. N., attached to the R. N. College. Illustrated. Svu. . 
MAIN and BROWN.— The Marine Steam-Engine. 

By Thomas J. Main, F. R. Ass't S. Mathematical Professor at the 
Royal Naval College, Portsmouth, and Thomas Brown, Assoc. 
Inst. C. E., Chief Engineer R. N. Attached to the Royal Naval 
College. With numerous illustrations. Svo. 
MAKINS.— A Manual of Metallurgy: 

By George Hogarth Makins. 100 engravings. Second edition 
rewritten and much enlarged. i2mo.. 592 pages 

MARTIN.— Screw-Cutting Tables, for the Use of Mechanica) 
Engineers : 
Shownig the Proper Arrangement of tVheels for Cutting the Threads 
of Screws of any Required Pitch ; with a Table for Making the Uni 
versal Gas-Pipe Thread and Taps. By W. A. Martin, Engineer. 
Svo 50 

MICHELL. — Mine Drainage: 
Being a Complete and Practical Treatise on Direct-Acting UiMler 
ground Steam Pumping Machinery. With a Description of a largt 
number of the best known Engines, their General Utility and ih« 
Special Sphere of their Action, the Mode of their Application, and 
their Merits compared with other Pumping Machinery. By StepHEM 
MiCHELL. Illustrated by 247 engravings. 8vo., 369 pages. $12.50 

MOLESWORTH.— Pocket-Book of Useful Formulae and 
Memoranda for Civil and Mechanical Engineers. 
By Guilford L. Molesworth, Member of the Institution of Civil 
Engineers, Chief Resident Engineer of the Ceylon Railway. Full- 
bound in Pocket-book form $l.oo 



riENRY CAREY BAIRD & CO.'S CATALUGUE. 19 

MOORE. — The Universal Assistant and the Complete Me 
chanic : 

Containing over one million Industrial Facts, Calculations, ReceiptS; 
Processes, Trades Secrets, Rules, Business Forms, Legal Items, Etc., 
ir» every occupation, from the Household to the Manufactory. Bj 
R. Moore. Illustrated by 500 Engravings. i2mo. . ;?2.5C 

MORRIS. — Easy Rules for the Maasurement of Earthworks : 
By means of the Prismoidal Formula. Illustrated with Numerous 
Wood-Cuts, Problems, and Examples, and concluded by an Exten- 
sive Table for finding the Solidity in cubic yards from Mean Areas. 
The whole being adapted for convenient use by Engineers, Surveyors 
Contractors, and others needing Correct Measurements of Earthwork 

By Elwood Morris, C. E. 8vo $1.$^ 

MAUCHLINE.— The Mine Foreman's Hand-Book 

Of Practical and Theoretical I-iformation on the Opening, Venti- 
lating, and Working of Collieries. Questions and Answers on Prac- 
tical and Theoretical Coal Mining. Designed to Assist Students and 
Others in Pa'^sing Examinations for Mine Foremanships. By 
Robert Mauchline, Ex-Inspector of Mines. A New, Revised and 
Enlarged Edition. Illustrated by 1 14 engravings. 8vo. 337 

pages $^.7$ 

NAPIER. — A System of Chemistry Applied to Dyeing. 

By James Napier, F. C. S. A New and Thoroughly Revised Edi- 
tion. Completely brought up to the present state of the Science, 
including the Chemistry of Coal Tar Colors, by A. A. Ff^quet, 
Chemist and Engineer. With an Appendix on Dyeing and CaiicG 
Printing, as shown at the Universal Exposition, Paris, 1867. Illus- 
trated. 8vo. 422 pages J?3.oo 

NEVILLE.— Hydraulic Tables, Coefficients, and Formulae, foi 
finding the Discharge of Water from Orifices, Notches, 
Weirs, Pipes, and Rivers : 
Third Edition, with Additions, consisting of New Formula for the 
Discharge from Tidal and Flood Sluices and Siphons ; general infor 
mation on Rainfall, Catchment-Basins, Drainage, Sewerage, Wa;e» 
Supply for Towns and Mill Power. Bv Tohn Neville. C. E. M R 
I. A. ; Fellow of the Royal Geological Society of Ireland. Thick 

I2mo $s.sc 

NEWBERY.— Gleanings from Ornamental Art of every 
style : 
Drawn from Examples in the British, South Kensington, Indian, 
Crystal Palace, and other Museums, the Exhibitions of 1851 and 
1862, and the best English and Foreign works. In a series of loo 
exquisitely drawn Plates, containing many hundred examples. By 

Robert Newbery. 410. (Scarce.) 

MICHOLLS. —The Theoretical and Practical Boiler-Maker aa< 
Engineer's Reference Book: 
Containing a variety of Useful Infonnation for Employers of Labor 
Fwemen a-vi Worltinji Boiler- Makers. Irou, Copper, and Tiixmiths 



20 HENRY CAREY BAlKD & CO.'S CATALOGUE. 

Draughtsmen, Engineers, the General Steam-using Public, and for th« 
Use of Science Schools and Classes. By SAMUEL NlCHOLLS. Illu*' 
trated by sixteen ])laies, i2mo. ..... $2.yi 

NICHOLSON.— A Manual of the Art of Bookbinding : 

Containing full instructions in the different Branches of forwarding. 
Gilding, and Finishing. Also, the Art of Marbling Book-edges and 
Paper. By James B. NiCH(JLS()N. Illustrated. l2mo., cloth ^2.25 

NICOLLS.— The Railway Builder: 

A Iland-Book for Estimating the Probable Cost of American Rail* 
way Construction and Equipment. By WlLLlAM J. NiCOLLS, Civil 
Engineer. lUustiated, full bound, pocket-book form . ^2.00 

NORMANDY.— The Commercial Handbook of Chemical An- 
alysis : 
Or Practical Instructions for the Determination of the Intrinsic oj 
Commercial Value of Substances used in Manufactures, in Trades, 
and in the Arts. By A. Normandy. New Edition, Enlarged, and 
to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S., 
thick i2mo. ......... Scarce 

NORRIS. — A Handbook for Locomotive Engineers and Ma- 
chinists: 
Comprising the Proportions and Calculations for Constructing Loco- 
motives ; Manner of Setting Valves; Tables of Squares, Cubes, Areas, 
etc., etc. By Septimus Norris, M. E. New edition. Illustrated. 
I2mo 5J.50 

NYSTROM.— A New Treatise on Elements of Mechanics : 
Establishing Strict Precision in the Meaning of Dynamical Terms ■ 
accompanied with an Appendix on Duodenal Arithmetic and Me 
trology. By John W. Nystrom, C. E. Illustrated. 8vo. $^.0 

NYSTROM.— On Technological Education and the Construc- 
tion of Ships and Screw Propellers : 
For Naval and Marine Engineers. By John W. Nystrom, Intt 
Acting Chief Engineer, U. S. N. Second edition, revised, with addi 
tional matter. Illustrated by seven engravings. i2mo. . ;j!i.2 

O'NEILL. — A Dictionary of Dyeing and Calico Printing: 

Containing a brief account of all the Substances and Processes 11 
use in the Art of Dyeing and Printing Textile Fabrics ; with Practical 
Receipts and Scientific Information. By CHARLES O'Neill, Analy- 
tical Chemist. To which is added an Essay on Coal Tar Colors and 
their application to Dyeing and Calico Printing. By A. A. Fesquet, 
Chemist and Engineer. With an appendix on Dyeing and Calico 
Printing, as shown at the Universal Exposition, Paris, 1867- 8vo., 
491 pages . . $^,cKi 

ORTON. — Underground Treasures*. 

How and Where to Find Them. A Key for the Ready Determination 
of ail the Useful Minerals within the United States. By James 
OrTON, A.m., Late Professor of Natural History in Vassar College, 
N. v.; author of the "Andes and the Amazon," etc. A New Edi- 
tion, with An Appendix on. Ore Deposits and Testing Minerals (1901). 
Illustrated ;Sl.5o 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 2t 



OSBORN— The Prospector's Field Book and Guide. 

In the Search For and the Easy Determination of Ores and Other 
Useful Minerals. By Prof. H. S. OsBORN, LL. D. Illustrated by 58 
Engravings. i2mo. Fifth Edition. Revised and Enlarged 

(1901) l>-50 

OSBORN — A Practical Manual of Minerals, Mines and Min- 
ing : 
Comprising the Physical Properties, Geologic Positions, Local Occur- 
rence and Associations of the Useful Minerals; their Methods of 
Chemical Analysis and Assay ; together with Various Systems of Ex- 
cavating and Timbering, Brick and Masonry Work, during Driving, 
Lining, Bracing and other Operations, etc. By Prof. H. S. Osborn, 
LL. D., Author of " The Prospector's Field- Book and Guide." 171 
engravings. Second Edition, revised. 8vo. . . . ^4-50 
OVERMAN.— Th« Manufacture of Steel : 
Containing the Practice and Principles of Working and Making Steel. 
A Handbook for Blacksmiths and Workers in Steel and Iron, W^ agon 
Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hard- 
ware, of Steel and Iron, and for Men of Science and Art. By 
Frederick Overman, Mining Engineer, Author of the " Manu- 
facture of Iion," etc. A new, enlarged, and revised Edition. By 
A. A. Fesql£T, Chemist and Engineer. i2mo. . . $1.50 
OVERMAN. — The Moulder's and Founder's Pocket Guide : 
A Treatise on Mouldingand Founding in Green-sand, Dry-sand, Loam, 
and Cement; the Moulding of Machine Frames, Mill-gear, Hollow- 
ware, Ornaments, Trinkets, Bells, and Statues; Description of Moulds 
for Iron, Bronze, Brass, and other Metals; Plaster of Paris, Sulphur, 
Wax, etc. ; the Construction of Melting Furnaces, the Melting and 
Founding of Metals ; the Composition of Alloys and their Nature, 
etc., etc. By Frederick Overman, M. E. A new Edition, to 
which is added a Supplement on Statuary and Ornamental Moulding, 
Ordnance, Malleable Iron Castings, etc. By A. A. Fesquet, Chem- 
ist and Engineer. Illustrated by 44 engravings. l2mo. . $2.00 
PAINTER, GILDER, AND VARNISHER'S COMPANION. 
Comprising the Manufacture and Test of Pigments, the Arts of Paint- 
ing, Graining, Marbling, Staining, Sign- writing, Varnishing, Glass- 
staining, and Gilding on Glass ; together with Coach Painting and 
Varnishing, and the Principles of the Harmony and Contrast of 
Colors. Twenty-seventh Edition. Revised, Enlarged, and in great 
part Rewritten. By William T. Brannt, Editor of " Varnishes, 
Lacquers, Printing Inks and Sealing Waxes." Illustrated. 395 pp. 

l2mo. . . . , i?I-50 

PALLETT. — The Miller's, Millwright's, and Engineer's Guide. 
Bv Henry Pallett. Illustrated. i2mo. . . . $2.00 



22 HENRV CAREY BAIRD & CO.'S CATALOGUE. 

PERCY.— The Manufacture of Russian Sheet-Iron. 

By John Percy, M. D., F. R. S. Paper. ... 25 cts. 
PERKINS.— Gas and Ventilation : 

Practical Treatise on Gas and Ventilation. Illustrated. l2mo. I1.25 
PERKINS AND STOWE.— A New Guide to the Shect-iron 
and Boiler Plate Roller : 
Containing a Series of Tables showing the Weight of Slabs and Piles 
to Produce Boiler Plates, and of the Weight of Piles and the Sizes of 
Bars to produce Sheet-iron ; the Thickness of the Bar Gauge 
in decimals; the Weight per foot, and the Thickness on the Bar or 
Wire Gauge of the fractional parts of an inch; the Weight per 
sheet, and the Thickness on the Wire Gauge of Sheet-iron of various 
dimensions to weigh 112 lbs. per bundle; and the conversion of 
Short Weight into Long Weight, and Long Weight into Short. 

^1.50 
POSSELT.— Recent Improvements in Textile Machinery Re- 
lating to Weaving : 
Giving the Most Modern Points on the Construction of all Kinds 
of Looms, Warpers, Beamers, Slashers, Winders, Spoolers, Reeds, 
Temples, Shuttles, Bobbins, Heddles, Heddle Frames, Pickers, 
Jacquards, Card .Stampers, etc., etc. 600 illus. . . ^3 00 

POSSELT.— Technology of Textile Design: 

The Most Complete Treatise on tiie Construction and Application 
of Weaves for all Textile Fabrics and the Analysis of Cloth. By E. 
A. I'osselt. 1,500 illustrations. 410. .... SS-OO 
POSSELT.— Textile Calculations: 

A Guide to Calculations Relating to the Manufacture of all Kinds 
of Yarns and Fabrics, tlie Analysis of Cloth, Speed, Power and Belt 
Calculations. By E. A. PossELT. Illustrated. 4to. . ^2.00 
REGNAULT.— Elements of Chemistry: 

By M. V. Regnault. Translated from the French by T. Forrest 
Betton, M. D., and edited, with Notes, by James C. Booth, Melter 
and Refiner U. S. Mint, and William L. Faber, Metallurgist and 
Mining Engineer. Illustrated by nearly 700 wood-engravings. Com- 
prising nearly 1,500 pages. In two volumes, 8vo., cloth . $6.00 
RICHARDS.— Aluminium : 

Its History, Occurrence, Properties, Metallurgy and Applications, 
including its Alloys. By JOSEPH W. Richards, A. C, Chemist and 
Practical Metallurgist, Member of the Deutsche Chemische Gesell- 
schaft. Illust. Third edition, enlarged and revised (1895) . <jf6.00 
RIFFAULT, VERGNAUD, and TOUSSAINT.— A Practical 
Treatise on the Manufacture of Colors for Painting : 
Comprising the Origin, Definition, and Classification of Colors; the 
Treatment of the Raw Materials ; the best Formulae and the Newest 
Processes for the Preparation of every description of Pigment, and 
the Necessary Apparatus and Directions for its Use ; Dryers ; th» 
Testing. Application, and Qualities of Paints, etc., etc. By MM. 
Fjffault, Vergnaud, and ToussAlKT, Revised and Edited by M. 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 2J 



F. Malepeyre. Translated from the French, by A. A. FESQUny 
Chemist and Engineer. Illustrated by Eighty engravings. In on^ 

vol., 8vo., 659 pages ^^' 

ROPER.— A Catechism of High- Pressure, or Non-Condensing 

Steam -Engines : , r c. 

Including the Modelling, Constructing, and Management of Steam- 
Enaines and Steam Boilers. With valuable illustrations. By Ste- 
PHEN Roper. Engineer. Sixteenth edition, revised and enlarged, 

iSmo., tucks, gilt edge ^2.00 

FOPER.— Engineer's Handy-Book: 

Containing a full Explanation of the Steam-Engine Indicator, and its 
Use and Advantages to Engineers and Steam Users. With Formulae 
for EstimatincT the Power of all Classes of Steam-Engines ; alsv.. 
Facts Figures Questions, and Tables for Engineers who wish to 
qualif^y Aemselves for the United Stales Navy, the Revenue Service, 
the Mercantile Marine, or to take charge of the Better Class of Sta- 
tionary Steam-Engines. Tenth edition. l6mo.. 690 pages, tucks, 
gilt edge ...••••••' "^^'^ 

ROPER — Hand-Book of Land and Marine Engines : 
Including the Modelling, Construction, Running, and Management 
of Lanf^ and Marine Engines and Boilers. With illustrations, ny 
Stephen Roper, Engineer. Sixth edition. i2mo.,ti'cks, gilt edge. 

$3-5° 
ROPER.— Hand-Book of the Locomotive : 

Including the Construction of Engines and Boilers, and the Construc- 
tion, Management, and Running of Locomotives. By Stephen 
Roper Eleventh edition. i8mo., tucks, gilt edge . ?2.5« 

ROPER —Hand-Book of Modern Steam Fire-Engines. 

With iliustrations. By STEPHEN Roper, Engineer. Fourth edition, 
i2mo., tucks, gilt edge . . ■ ■ _ ■ ■ • ^3-5*' 
ROPER. — Questions and Answers for Engineers. 

This little book contains all the Questions that Engineers will be 
asked when undergoing an Examination for the purpose of procuring 
Licenses, and they are so plain that any Engineer or Fireman of or 
dinary intelligence may commit them to memory in a short time.^ By 
Stephen Roper, Engineer. Third edition . . • JS2.00 
ROPER.— Use and Abuse of the Steam Boiler. 

By Stephen Roper, Engineer. Eighth edition, with illustrations. 

l8mo., tucks, gilt edge #2.00 

ROSE.— The Complete Practical Machinist : 

Embracing Lathe Work, Vise Work, Drills and Drilling, Taps and 
Dies, Hardening and Tempering, the Making and Use of Tooli 
Tool Grinding, Marking out Work, Machine Tools, etc. By JosHUA 
Rose. 395 Engravings. Nineteenth Edition, greatly Enlarged with 
New and Valuable Matter. i2mo., 504 pages. . . $2.50 

ROSE.— Mechanical Drawing Self-Taught : 

Comprising Ini^tructions in the Selection and Preparation of Drawing 
Instruments, Elementarv Instruction in Practical Mechanical Draw- 



24 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

ing, together with Examples in Simple Geometry and Elementary 
Mechanism, including Screw Threads, Gear Wheels, Mechanical 
Motions, Engines and Boilers. By JosiiUA RoSE, M. E. Illustrated 
by 330 engravings. 8vo , 313 pages .... $4.00 

ROSE.— The Slide- Valve Practically Explained: 

Embracing simple and com|ilete Practical Demonstrations of th 
operation of each element in a Slide-valve Movement, and illustrat- 
ing the effects of Variations in their Proportions by examples care- 
fully selected from the most recent and successful practice. By 
Joshua Rose, M. E. Illustrated by 35 engravings . Ji.oo 

ROSS. — The Blowpipe in Chemistry, Mineralogy and Geology: 

Containing all Known Methods of Anhydrous Analysis, many Work- 
ing Examples, and Instructions for Making Apparatus. By LlEUT.- 
COLONEL \N. A. Ross, R. A., F. G. S. With 120 Illustrations. 
i2mo. .......... 32.00 

SHAW.— Civil Architecture : 

Being a Complete Theoretical and Practical System of Building, con« 
taining the Fundamental Principles of the Art. By Edward Shaw, 
Architect. To which is added a Treatise on Gothic Architecture, etc. 
By Thomas W. Sili.oway and George M. Harding, Architects. 
The whole illustrated by 102 quarto plates finely engraved on copper. 
Eleventh edition. 4to. ....... J6.00 

SHUNK. — A Practical Treatise on Railway Curves and Loca- 
tion, for Young Engineers. 
By W. F. Shunk, C. E. l2mo. tuU bound pocket-book form $2.00 

SLATER.— The Manual of Colors and Dye Wares. 

By J. W. Slater. i2mo 33-oo 

SLOAN. — American Houses : 

A variety of Original Designs for Rural Buildings. Illustrated by 
26 colored engravings, with descriptive references. By Samukl 
Sloan, Architect. 8vo. .75 

SLOAN. — Homestead Architecture: 

Containir.g Forty Designs for Villas, Cottages, and Farm-houses, with 
Ei;says on Style, Construction, Landscape Gardening, Furniture, etc., 
etc. THustrated by up'^ards of 200 engravings. By SAMUEL Sloan, 
Architect. 8vo. ... .... J?2.5o 

8LOANE. — Ho.re Experiments m Science. 

By T. O'Conor Slca>ne, E. M., A. M., Fh. O. Illustrated by 91 
engravings. i2mo. ....... Jl.oo 

SMEATON.— Builder's Pockt^- Companion : 

V Containing the Elements of Building, Surveying, and Architecture; 

with Practical Rules and Instructions co.:nected with the subject. 

By A. C. Smeaton, Civil Engineer, etc. i2mo. 
SMITH. — A Manual of Political Economy. 

By E. Peshine Smith. A New Edition, to which is added a full 

Index. i2mo . . ^l 25 



HENRY CAREY EAIRD & CO.'S CATALOGUE. 25 



SMITH. — Parks and Pleasure- Grounds : 

Or Practical Notes on Country Residences, Villas, Public Parks, and 
Gardens. By Charles H. J. Smith, Landscape Gardener and 
Garden Architect, etc., etc. l2mo. .... ;$2.oo 

SMITH.— The Dyer's Instructor : 

Comprising Practical Instructions in the Art of Dyeing Silk, Cotton, 
Wool, and Worsted, and Woolen Goods ; containing nearly 800 
Receipts. To which is added a Treatise on the Art of Padding; ancjj 
the Printing of Silk Warps, Skeins, and Handkerchiefs, and the| 
various Mordants and Colors for the different styles of such work/ 
By David Smith, Pattern Dyer. i2mo. . . . ^r.50'1 

Smyth. — a Rudimentary Treatise on Coal and Coal-Mining. 
By Warrington W. Smyth, M. A., F. R. G., President R. G. S. 
of Cornwall. Fifth edition, revised and corrected. With xiumer- 
ous illustrations. l2mo. ...... ^1.75 

SNIVELY.— Tables for Systematic Qualitative Chemical AnaK 
ysis. 
By John H. Snively, Phr. D. 8vo. ... $1.00 

SNIVELY.— The Elements of Systematic Qualitative n^hemicaJ 
Analysis : 
A Hand-book for Beginners. By John H. Snively, Phr. D. i6mo. 

$2.00 

STOKES. — The Cabinet-Maker and Upholsterer's Companion : 
Comprising the Art of Drawing, as applicable to Cabinet Work; 
Veneering, Inlaying, and Buhl-Work; the Art of Dyeing and Stain' 
ing Wood, Ivory, Bone, Tortoise-Shell, etc. Directions for Lacker 
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Cements, and Compos" ns; with numerous Receipts, useful to work 
men generally. Bv Stokes. Illustrated. A New Edition, with 
an Appendix upor .ench Polishing, Staining, Imitating, Varnishing, 
etc., etc. i2mo ........ ^1.25 

STRENGTH AND OTHER PROPERTIES OF METALS; 
Reports of Expernnents on the Strength and other Properties of 
Metals for Cannon. With a Description of the Machines for Testing 
Metals, and of the Classification of Cannon in service. By Officers 
of the Ordnance Department, U. S. Jirmy. By authority of the Secre- 
tary of War. Illustrated by 25 large steel plates. Quarto. $S-00 

SULLIVAN. — Protection to Native Industry. 
By Sir Edward Sullivan, Baronet, author of " Ten Chapters 011 
Social Reforms." 8vo. ....... ^i.oa 

SHERRATT.— The Elements of Hand-Railing : 

Simplified and Explained in Concise Problems that are Easily Under- 
stood. The whole illustrated with Thirty-eight Accurate and Origi- 
nal Plates, Founded on Geometrical Principles, and Showing how to 
Make Rail Without Centre Joints, Making Better Rail of the Same 
Material, with Half the Labor, and Showing How to Lay Out Stairs 
of all Kinds. By R. J. Sherratt. Folio. . . . ^12.50 



2fi HENRY CAREY BAIRt» & CO.'S CATALOGUE. 

SYME. — Outlines of an Industrial Science. 

By Daviu Symk. 121110, . . ... $2.00 

TABLES SHOWING THE WEIGHT OF ROUND, 
SQUARE, AND FLAT BAR IRON, STEEL, ETC., 
By Mcasurenicnl. Cloth ...... 63 

TAYLOR.— Statistics of Coal : 

Including Mineral Bituminous Substance^ employed in Arts and 
Manulactures; with their Geographical, Geo.ogical, and Commercial 
Distribution and Amount of Production and Consumption on the 
American Continent. With Incidental Statistics of the Iron Manu- ' 
facture. By R. C. Taylor. Second edition, revised by S. S. Halde- 
MAN. Illustrated by five Maps and many wood engravings. 8vo., 
cloth ^6.00 

TEMPLETON.— The Practical Examinator on Steam and the 
Steam-Engine : 
With I.iistructive References relative thereto, arranged for the Use of 
Engineers, Students, and others. By William Templeton, En- 
gineer. i2mo. ........ $1.00 

THAUSING.— The Theory and Practice of the Preparation of 
Malt and the Fabrication of Beer: 
With especial reference to the Vienna Process of Brewing. Elab- 
orated from personal experience by JuLlUS E. Thausing, Professor 
at the School for Brewers, and at the Agricultural Institute, Modling, 
near Vienna. Translated from the German by William T. Brannt, 
Thoroughly and elaborately edited, with much American matter, and 
according to the latest and most Scientific Practice, iiy A. ScHWARZ 
and Dr. A. H. Bauer. Illustrated by 140 Engravings. 8vo., 815 
pages $10.00 

THOMPSON.— Political Economy. With Especial Reference 
to the Industrial History of Nations : 
By Robert E. Thompson, M. A., Professor of Social Science in the 
University of Pennsylvania. i2mo. .... $1.50 

THOMSON.— Freight Charges Calculator: 

By Andrew Thomson, Freight Agent. 24mo. . . ^1.25 

TURNER'S (THE) COMPANION: 

Containing Instructions in Concentric, Elliptic, and Eccentric Turn, 
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Directions for using the Eccentric Cutter, Drill, Vertical Cutter, and 
Circular Rest; with Patterns and Instructions for working them. 
l2mo. ^I.OO 

TURNING: Specimens of Fancy Turning Executed on the 

Hand or Foot- Lathe : 

With Geometric, Oval, and Eccentric Chucks, and Elliptical Cutting 

Frame. By an Amateur. Illustrated by 30 exquisite Photographs. 

4to. $2.50 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 27 



'VAILE. — Galvanized-Iron Cornice-W^orker's Manual: 

Containing Instructions in Laying out the Different Mitres, and 
Making Patterns for all kinds of Plain and Circular Work. Also, 
Tables of Weights, Areas and Circumferences of Circles, and other 
Matter calculated to Benefit the Trade. By Charles A. Vaile. 

Illustrated by twenty-one plates. 4to ^5.00 

VILLE. — On Artificial Manures : 
Their Chemical Selection and Scientific Application to Agriculture. 
A series of Lectures given at the E.xperimental Farm at Vincennes, 
during 1867 and 1874-75. By M. Georges Ville. Translated and 
Edited by William Crookes, F. R. S. Illustrated by thirty-one 
engravings. 8vo., 450 pages ...... ^6.00 

VILLE.— The School of Chemical Manures : 
Or, Elementary Principles in the Use of Fertilizing Agents. From 
the French of M. Geo. Ville, by A. A. Fesquet, Chemist and En- 
gineer. With Illustrations. i2mo. .... ^1.25 

VOGDES. — The Architect's and Builder's Pocket -Companioa 
and Price-Book : 

Consisting of a Shoit but Comprehensive Epitome of Decimals, Duo- 
decimals, Geometry and Mensuration ; with Tables of United States 
Measures, Sizes, Vveights, Strengths, etc., of Iron, Wood, Stone, 
Brick, Cement and Concretes, Quantities of Materials in given Sizes 
and Dimensions of Wood, Brick and Stone; and full and complete 
Bills of Prices for Carpenter's Work and Painting ; also. Rules for 
Computing and Valuing Brick and Brick Work, Stone Work, Paint- 
ing, Plastering, with a Vocabulary of Technical Terms, etc. By 
Frank W. Vogdes, Architect, Indianapolis, Ind. Enlarged, revised, 
and corrected. In one volume, 368 pages, full-bound, pocket-book 
form, gilt edges ........ $2.00 

Cloth . . 1.50 

VAN CLEVE.— The English and American Mechanic : 

Comprising a Collection of Over Three Thousand Receipts, Rules, 
and Tables, designed for the Use of every Mechanic and Manufac- 
turer. By B, Frank Van Cleve. Illustrated. 500 pp. i2mo. ^2.00 

WAHNSCHAFFE.— A Guide to the Scientific Examination 
of Soils : 
Comprising* Select Methods of Mechanical and Chemical Analysis 
and Physical Investigation, Translated from the German of Dr. F. 
Wahnschaffe. With additions by WiLLiAM T. Brannt. Illus- 
trated by 25 engravings. i2mo. 177 pages . . , $l.SO 

WALL. — Practical Graining : 

With Descriptions of Colors Employed and Tools Used. Illustrated 
by 47 Colored Plates, Representing the Various Woods Used M 
Interior Finishing. By William E. Wall. 8vo. (Scarce.) 

WALTON.— Coal-Mining Described and Illustrated: 
By Thomas H. Walton, Mining Engineer. Illustrated by 24 Jargi 
and elaborate Plates, after Actual Workings and Apparatus, JS.oo 



2S liENRY CAREY BAIRD & CO.'S CATALOGUE, 

WARE.— The Sugar Beet. 

Including a History of the Beet Sugar Industry in Europe, Varietie' 
of the Sugar Beet, Kxnmination, Soils, Tillage, Seeds and Sowing 
Yield and Cost of Cultivation, Harvesting, Transportation, Conserva 
tion. Feeding Qualities of the Beet and of the Pulp, etc. By Lewi{ 
S. Ware, C. E., M. E. Illustrated by ninety engravings. 8vo. 

$4.QQ 

WARN.— The Sheet-Metal Worker's Instructor: 

VoT Zinc, Sheet-Iron, Copper, and Tin-Plate Workers, etc. Contain- 
ing a selection of Geometrical Problems ; also. Practical and Simple 
Rules for Describing the various Patterns required in the different 
branches of the above Trades. By Reuben H. Warn, Practical 
Tin-Plate Worker. To which is added an Appendix, containing 
Instructions for Boiler-Making, Mensuration of Surfaces and Solids, 
Rules for Calculating the Weights of different Figures of Iron and 
Steel, Tables of the Weights of Iron, Steel, etc. Illustrated by thirty- 
two Plates and thirty-seven Wood Engravings. 8vo. . $3.00 

WARNER. — New Theorems, Tables, and Diagrams, for tha 
Computation of Earth-work : 

Designed for the u^e of Engineers in Preliminary and Final Estimates 
of Students in Engineering, and of Contractors and other non-profes- 
sional Computers. In two parts, with an Appendix. Part I. A Prac- 
tical Treatise; Part II. A Theoretical Treatise, and the Appendix., 
Containing Notes to the Rules and Examples of Part I.; Explana- 
tions of the Construction of Scales, Tables, and Diagrams, and Z 
Treatise upon Equivalent Square Bases and Equivalent Level Heights, 
By John Warner, A. M., Mining and Mechanical Engineer. Illus- 
trated by 14 Plates. 8vo. ...... ^S-O^ 

WILSON. — Carpentry and Joinery: 

By John Wilson, Lecturer on Building Construction, Carpentry and 
Joinery, etc., in the Manchester Teciinical School. Third Edition, 
with 65 full page plates, in flexible cover, oblong . . .80 

WATSON. — A Manual of the Hand-Lathe : 

Comprising Concise Directions for Working Metals of all kinds, 
Ivory, Bone and Precious Woods; Dyeing, Coloring, and French 
Polishing; Inlaying by Veneers, and various methods practised to 
produce Elaborate work with Dispatch, and at Small Expense. By 
Egbert P. Watson, Author of " The Modern Practice of American 
Machinists and Engineers." Illustrated by 78 engravings. ;Sl.SO 

WATSON. — The Modern Practice of American Machinists and 
Engineers 
Including the Construction, Application, and Use of Drills, Latlio 
Tools, Cutters for Boring Cylinders, and Hollow-work generally, with 
the most Economical Speed for the same ; the Results verified bj 
Actual Practice at the Lathe, the Vise, and on the Floor. Togetho 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 29 

with Workshop Management, Economy of Manufacture, the Steam 
Engine, Boilers, Gears, Belting, etc., etc. By Egbert P. Watson. 
Illustrated by eighty-six engravings. i2mo. . . . ^^2.50 

WATT. — The Art of Soap Making : 

A Practical Hand-Book of the Manufacture of Hard and Soft Soaps, 
Toilet Soaps, etc. Fifth Edition, Revised, to which is added an 
Appendix on Modern Candle Making. By Alexander Watt. 
111. i2mo. . $3.00 

WEATHERLY.— Treatise on the Art of Boiling Sugar, Crys- 
tallizing, Lozenge-making, Comfits, Gum Goods, 
And other processes for Confectionery, etc., in which are explained, 
:in an easy and familiar manner, the various Methods of Manufactur- 
ing every Description of Raw and Refined Sugar Goods, as sold by 
Confectioners and others. l2mo. ..... ?l-50 

^WILL.— Tables of Qualitative Chemical Analysis : 

With an Introductory Chapter on the Course of Analysis. By Pro- 
fessor Heinrich Will, of Giessen, Germany. Third American, 
from the eleventh German edition. Edited by Charles F. Himp:s, 
Ph. D., Professor of Natural Science, Dickinson College, Carlisle, 
Pa. 8vo ^i-5o 

WILLIAMS.— On Heat and Steam : 

Embracing New Views of Vaporization, Condensation and Explo- 
sion. By Charles Wye Williams, A. I. C. E. Illustrated. 8vo. 

1^2.50 

WILSON. — First Principles of Political Economy: 

With Reference to Statesmansliip and the Progress of Civilization. 
By Professor W. D. Wilson, of the Cornell University. A new and 
revised edition. i2mo. ....... $1-$'^ 

"WILSON.— The Practical Tool-Maker and Designer: 

A Treatise upon the Designing of Tools and Fixtures for Machine 
Tools and Metal Working Machinery, Comprising Modern Examples 
of Machines with Fundamental Designs for Tools for the Actual Pro- 
duciion of the work; Together with Special Reference to a Set of 
Tools for Machining the Various Parts of a Bicycle. Illustrated by 
189 engravings. 1898. ....... $2.50 

CONTENTS: Introductory. Chapter I. Modern Tool Room and Equipment. 
IL Files, Their Use and Abuse. III. Steel and Tempering. IV. Making Jigs. 
V. Milling Machine Fixtures. VI. Tools and Fixtures for Screw Machines. VII. 
Broaching. VIII. Punches and Dies for Cutting and Drop Press. IX. Tools for 
Hollow- Ware. X. Embossing : Metal, Coin, and Stamped Sheet-Metal Orna- 
ments. XI. Drop Forging. XII. Solid Drawn Shells or Ferrules; Cupping or 
Cutting, and Drawing ; Breaking Down Shells. XIII. Annealing, Pickling and 
Cleaning. XIV. Tools for Draw Bench. XV. Cutting and Assembling Pieces 
by Means of Ratchet Dial Plates at One Operation. XVI. The Header. XVII. 
Tools for Fox Lathe. XVIII. Suggestions for a Set of Tools for Machining the 
Various Parts of a Bicycle. XIX. The Plater's Dynamo. XX. Conclusion — 
With a Few Random Ideas. Appendix. Index. 

"WOODS. — Compound Locomotives: 

By Arthur Tannatt Woods. Second edition, revised and enlarged 
by David Leonard Barnes, A M., C. E. 8vo. 330 pp. $3or 



30 HENRY CAREY BAIRD & CO.'S CATALOGUE. 



WOHLER.— A Hand-Bookof Mineral Analysis: 

By F. WollLER, Professor of Chemistry in the University of Gottin- 
gen. Edited by Henry B. Nason, Professor of Chemistry in the- 
Renssalaer Polytechnic Institute, Troy, New York. Illustrated. 
i2mo. 

WORSSAM. — On Mechanical Saws: 

From the Transactions of the .Society of Engineers, 1869. By S. W. 
WoRssAM, Jr. Illustrated by eighteen large plates. 8vo. $1.50 



RECENT ADDITIONS. 

BRANNT. — Varnishes, Lacquers, Printing Inks and Sealing-' 1 
Waxes : 

Their Raw Materials and their Manufacture, to which is added the 
Art of Varnishing and Lacquering, including the Preparation of Put- 
ties and of .Stains for Wood, Ivory, Bone, Horn, and Leather. By 
William T. Brannt. Illustrated by 39 Engravings, 338 pages. 

i2mo ,$3.00 

BRANNT — The Practical Scourer and Garment Dyer: 

Comprising Dry or Chemical Cleaning; the Art of Removing Stains; 
F"ine Washing; Bleaching and Dyeing of Straw Hats, Gloves, and 
Feathers of all kinds; Dyeing of Worn Clothes of all fabrics, in- 
cluding Mixed Goods, by One Dip; and the Manufacture of Soaps 
and Fluids for Cleansing Purposes. Edited by William T. Brannt, 
Editor of "The Techno-Chemical Receipt Book." -Illustrated. 
203 pages. i2mo. ..... $2.00 

BP AN NT.— Petroleum. 

its History, Origin, Occurrence, Production, Physical and Chemical 
Constitution, Technology, Examination and Uses; Together with 
the Occurrence and Uses of Natural Gas. Edited chiefly from the 
German of Prof. Hans Hoefer and Dr. Alexander Veith, by Wm. 
T. Brannt. Illustrated by 3 Plates and 284 Engravings. 743 pp. 
8vo. ^57.50 

BRANNT. — A Practical Treatise on the Manufacture of Vine- 
gar and Acetates, Cider, and Fruit- Wines : 
Preservation of Fruits and Vegetables by Canning and Evaporation ; 
Preparation of Fruit-Butters, Jellies, Marmalades, Catchups, Pickles,. 
Mu.stards, etc. Edited from various sources. By William T. 
Brannt. Illustrated by 79 Engravings. 479 pp. 8vo. ^6.00 

BRANNT.— The Metal Worker's Handy-Book of Receipts 
and Processes : 
Being a Collection of Chemical Formulas and Practical Manipula- 
tions for the working of all Metals ; including the Decoration and 
Beautifying of Articles Manufactured therefrom, as well as their 
Preservation. Edited from various sources. By WiLLIAM T. 
Brannt. Illustrated. lamo. I2.50- 



HENRY CAREY BAIRD & CO.'S CATALOGUE. 



OBiTE.— ^ Practical Treatise on the Manufacture cf Per* 
lumery. 
Comprisins: directions for making all kinds of Perfumes, Sachet 
Powders, Fumigatini^ Materials, Dentifrices, Cosmetics, etc., with a 
full account of the V ilatile Oils, Balsams, Resins, and other Natural 
and Artificial Perfume-substances, including the Manufacture of 
Fruit Ethers, and tests of their purity. By Dr. C. Deite, assisted 
by L. BoRCHERT, F. Eichbaum, E. Kugi.er, H. Toeffner, and 
other experts. From the German, by Wm. T. Brannt. 28 Engrav- 
ings. 358 pages. 8vo. |3'30 

^LDWARDS. — American Marine Engineer, Theoretical ani^ 
Practical : 
With Examples of the latest and most approved American Practice. 
By Emory Edwards. 85 illustrations. i2mo. . . ^2.50 

EDWARDS.— 900 Examination Questions and Answers: 

For Engineers and Firemen (Land and Marine) who desire to ob- 
tain a United States Government or State License. Pocket-book 

form, gilt edge $i-5*^ 

KIRK. — The Cupola Furnace: 

A Practical Treatise on the Construction and Management of Foun- 
dry Cupolas. By Edward Kirk, Practical Moulder and Melter, 
author of "The Founding of Metals." Illustrated by 80 Engravings. 
8vo. (1899) I3.50 

POSSELT. — The Jacquard Machine Analysed and Explained : 

With an Appendix on the Preparation of Jacquard Cards, and 
Practical Hints to Learners of Jacquard Designing. By E. A. 
PossELT. With 230 illustrations and numerous diagrams. 127 pp. 
4to $3°0 

POSSELT.— The Structure of Fibres, Yarns and Fabrics: 

Being a Practical Treatise for the Use of all Persons Employed in 
the Manufacture of Textile Fabrics, containing a Description of the 
Growth and Manipulation of Cotton, Wool, Worsted, Silk Flax, 
Jute, Ramie, China Grass and Hemp, and Dealing with all Manu- 
facturers' Calculations for Every Class of Material, also Giving, 
Minute Details for the Structure of all kinds of Textile Fabrics, and 
an Appendix of Arithmetic, specially adapted for Textile Purposes. 
By E. A. PossELT. Over 400 Illustrations, quarto. . $5.00 

RICH. — Artistic Horse-Shoeing : 

A Practical and Scientific Treatise, giving Improved Methods of 
Shoeing, with Special Directions for Shaping Shoes to Cure Different 
Diseases of the Foot, and for the Correction of Faulty 'Action in 
Trotters. By George E. Rich. 62 Illustrations. 153 pages, 
lama $1.00 



32 HENRY CAREY BAIRD & CO.'S CATALOGUE. 

RICHARDSON.— Practical Blacksmithing : 

A Collection of Articles Contributed at Different Times by Skilled 
Workmen to the columns of " The Blacksmith and Wheelwright," 
and Covering nearly the Whole Range of Blacksmithing, from the 
Simplest Job of Work to some of the Most Complex Forgings, 
Compiled and Edited by M. T. Richardson. 

Vol.1. 2IO Illustrations. 224 pages. i2mo. . . Ji.oo 

Vol. II. 230 Illustrations. 262 pages. l2mo. . . ;$i.oo 
Vol. III. 390 Illustrations. 307 pages. i2mo, . , i^i.oo 
Vol. IV. 226 Illustrations. 276 pages. l2mo. , , ^i.oo 

RICHARDSON-— The Practical Horseshoer: 

Being a Collection of Articles on Horseshoeing in all its Branche* 
which have appeared from time to time in the columns of " 1 he 
Blacksmith and Wheelwright," etc. Compiled and edited by M. T. 
Richardson. 174 illustrations. ..... Ji.oo 

ROPER. — ^Instructions and Suggestions for Engineers and 
Firemen : 
By Stephen Roper, Engineer. i8mo. Morocco . ;f2.oo 
ROPER. — The Steam Boiler: Its Care and Management: 

By Stephen Roper, Engineer. i2mo., tuck, gilt edges. $2.00 
ROPER. — The Young Engineer's Own Book: 

Containing an Explanation of the Principle and Theories on which 
the Steam Engine as a Prime Mover is Based. By Stephen Roper, 
Engineer. 160 illustrations, 363 pages. iSmo., tuck . $2.50 

ROSE. — Modern Steam- Engines: 

An Elementary Treatise upon the Steam-Engine, written in Plain 
language ; for Use in the Workshop as well as in the Drawing Office, 
Giving Full Explanation; of the Construction of Modern Steanv 
Engines : Including Diagrams showing their Actual operation. To- 
gether with Complete but Simple Explanations of the operations of 
Various Kinds of Valves, Valve Motions, and Link Motions, etc., 
thereby Enabling the Ordinary Engineer to clearly Understand the 
Principles Involved in their Construction and Use, and to Plot out 
their Movements upon the Drawing Board. By Joshua Rose. M. E. 
Illustrated by 422 engravings. Revised. 358 pp. . . ;SS6.00 

ROSE.— Steam Boilers: 

A Practical Treatise on Bfdler Construction and Examf nation, for the 
Use of Practical Boiler Makers, Boiler Users, and Inspectors; and 
embracing in plain figures all the calculations necessary in Designing 
or Classifying Steam Boilers. By Joshua Rose, M. E. Illustrated 
by 73 engravings. 250 pages. 8vo. .... $2.50 

6CHRIBER.— The Complete Carriage and Wagon Painter: 
A Concise Compendium of the Art of Painting Carriages, Wagons, 
and Sleighs, embracing Full Directions in all the Various Branches, 
including Lettering, Scrolhng, ♦manienting, Striping, Varnishing, 
and Coloring, with numerous Recipes for Mixing Colore. 73 Illus- 
f-ations. 177 pp. l2mo. ...... $l.OO 



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